Stob Coire nan Lochan Database of British and Irish Hills


Printable pdf version of the Database Notes
Changes and issues
in RHB Section order
Channel Islands


The Database of British and Irish Hills (DoBIH) was founded in 2001. Its twin objectives are to present the most accurate hill data for lists that meet our criteria of notability and demand, and to provide logging facilities for baggers. The evolution of the database can be followed in a series of Marhofn articles. The editorial team (in order of joining) comprises Graham Jackson, Chris Crocker, John Barnard, Simon Edwardes, George Gradwell, Mark Jackson, Jim Bloomer and Dave Marshall.

The database is provided in two principal formats: an Access database, from which Excel and csv versions are derived, and an online database accessible at Hill Bagging. Both formats offer logging facilities, with personal ascent records readily transferable between the two. Hill Bagging does not return the fields with absolute grid reference, latitude/longitude (except by reading off the map) or revision date, but includes links to photographs on the hill summits website. Hill Bagging is continuously updated with changes to lists and data and is therefore the most up to date. New versions of the downloadable database are currently issued at approximately 4 month intervals. Significant changes to hill lists (except Tumps below 500m and subs) between releases are communicated via newsflashes on this site. These and other changes, including those to minor Tumps, are also announced on Hill Bagging when they enter the database.

We place no restrictions on use of the data by third parties and enourage authors of other websites and applications to do so. We just ask users to observe the terms of the Creative Commons licence.

Many hills occur in more than one list, which may give different data in the original sources. Where a list author has chosen a different location for the summit, we have recorded this in the database. In cases where the locations could be regarded as separate summits we have listed the hills separately. This can be a subjective decision; we hope the majority of users will agree with our choices. Occasionally a list author's classification is at odds with our data; these are tabulated in a list of discrepancies.

If you find any errors or wish to query data, please email the authors at the address on the home page.

Summary of lists

The following table summarises the main lists included in the database. It excludes subs, Marilyn and Hump Twin Tops and a few historic and subjective lists (Bridge, Buxton & Lewis, Dillon, Trail 100). More information on the individual lists is given in Definitions and Background.

Some lists are subsets of other lists. For example, the Marilyns are a subset of the Humps, the Grahams are a subset of the Marilyns, and many lists are subsets of the Tumps. Some lists are not exact subsets due to discrepancies between lists.

National lists
Scotland England and Wales Ireland
  any 150+ Marilyn Marilyn Marilyn
  any 100+ Hump Hump Hump
  any 30+ Tump Tump  
3000+ 914.4+ undefined Munro, Munro Top Furth Furth
3000+ 914.4+ 30+ Murdo2 Hewitt Hewitt
2500-2999 762.0-914.3 152.4+ (500ft)3 Corbett
2500-2999 762.0-914.3 30+ Corbett Top2
2000-2499 609.6-761.9 150+ Graham
2000-2499 609.6-761.9 30+ Graham Top2
600+ 30+ Simm Simm Simm
2000+ 609.6+ 15+   Nuttall
  600+ 15+     Vandeleur-Lynam
  500-609.5 30+ Donald Dewey
Highland Five
Dewey Myrddyn Dewey
  500+ 30+     Arderin
  400-499.9 30+     Carn
  100-399.9 100+     Binnion
  n/a n/a County Tops4
  n/a see5 SIBs  

1 For lists where the current or original definition is expressed in feet
2 These categories have been superseded by the Simms
3 1691 Kirriereoch Hill is the only hill within this height range with a drop between 150 and 152.4m. It was
   deleted from the Corbetts in 1984 and added to the Marilyns in 2015
4 See County Tops for subsets
5 Islands having at least 30m drop or 30 hectares area excluding sea stacks; see SIBs

The Isle of Man is included in the listings of British Marilyns, Humps, Tumps and Deweys, but not in Simms, Hewitts, Nuttalls or SIBs. Some older lists of British 2000ft hills, including Bridge and Buxton & Lewis, include Snaefell on the Isle of Man.

The Channel Islands are included in the British Humps and Tumps.

Regional lists
Region List
2000+ 609.6+ 30.48+ (100ft)1 Southern Uplands Donald
2000+ 609.6+ 30.48+ (100ft)2 Southern Uplands Donald Top
1000+3 304.8+3 undefined Lake District Wainwright
undefined undefined undefined Lake District Wainwright Outlying Fell
1000+ 304.8+ undefined Lake District Birkett
  300+3 undefined Lake District Synge
undefined undefined undefined Lake District Fellranger

1 As for Donald Tops but more than 17 units from the main top of the 'Hill' to which it belongs, where a unit is either one-twelfth of a mile measured along the connecting ridge or one 50-foot contour between the lower Top and its connecting col
2 Plus peaks of sufficient topographical merit between 50ft and 100ft
3 Except Castle Crag

Background to the lists

The first list of British hills to gain popularity, of Scottish mountains over 3000 feet high, was compiled by Sir Hugh Munro in 1891. The Munros were joined by the Corbetts and Donalds and became well known thanks to their publication in Munro's Tables. It took a surprisingly long time for a definitive list of Scottish hills in the range 2000-2500 feet to appear, but in the 1997 edition of Munro's Tables the SMC adopted the list of Grahams that Alan Dawson had published in 1992. Of Dawson's other Scottish lists, the Murdos (1995) and the New Donalds (1995) were motivated by a desire to bring objectivity to the classification of Munro Tops and Donalds. Breaking new ground was Corbett Tops and Corbetteers (1999). Corbett Tops include subsidiary summits of Munros and Corbetts within the Corbett height range. This was followed by Graham Tops and Grahamists (2004). This last list subsumes the New Donalds. The last four publications, and three similar ones listing the Hewitts of England, Wales and Ireland, were published by TACit Press but the majority are now out of print. In June 2010 Dawson created the Simms (Six-hundred Metre Mountains; originally called Sims) by combining the Murdos, Corbett Tops, Graham Tops and Hewitts and lowering the height threshold to 600m. The Simms Hall of Fame requires the ascent of 2000 British Simms.

Completions of the Munros (with Tops and Furths) are recorded by the SMC. The SMC also records completions of Corbetts, Grahams and Donalds by those who have completed the Munros. Completions of Corbetts are recorded by Dave Hewitt. Completions of Grahams and Simms are recorded by Alan Dawson in the Relative Hills of Britain website.

Outside Scotland, the Hewitts (Hills in England, Wales and Ireland over Two Thousand feet high), together with the Nuttalls in England and Wales, are the most accurate and up-to-date of a succession of publications listing the 2000-foot summits. In Ireland, a popular list in recent years is The Mountains of Ireland by Paddy Dillon. A listing of Irish hills equivalent to the Nuttalls was superseded in 1997 by a metric equivalent, the Vandeleur-Lynams. Some of the earlier lists are of historical interest but for practical use most people will have little reason to look beyond those mentioned above. However we acceded to requests to include Buxton & Lewis (1986) and Bridge (1973). The last two lists are defined by the original publication and are not subject to revision. The lists of Elmslie, Simpson and Moss have been republished online by Moss.

Completions of the English, Welsh and Irish 2000-foot hills are recognised by the Long Distance Walkers Association (LDWA). It might be thought unreasonable to treat England and Wales as one country, but only The Nuttalls will record completions of one list without the other.

The first publication to list the 500m tops of England and Wales was Michael Dewey's Mountain Tables in 1995. They effectively extend the Hewitts down to 500m. Completions are recorded by the LDWA. The Deweys were extended to Ireland (the Myrddyn Deweys) by Michael Dewey and Myrddyn Phillips in 2000, and to the Scottish Lowlands (Donald Deweys) by David Purchase in 2001. Hitherto, 500m hills in the Scottish Highlands have not had a separate identity, but a complete listing of Scottish 500m hills was compiled by Rob Woodall using data from Tony Payne, Clem Clements, John Kirk and others and uploaded to the rhb group (2003, revised 2006). To distinguish the Highland hills from the Donald Deweys in searches etc. we have named them Highland Fives. All the 500m lists have been comprehensively revised since their original publication.

In Ireland, MountainViews has built on data from other sources to create the Arderins for hills over 500m high and the Carns for hills in the 400–500m range. In 2013 it published A Guide to Ireland's Mountain Summits: The Vandeleur-Lynams & The Arderins, reprinted with revisions in 2015.

The Marilyns was the first list with a criterion on drop alone, and none on height. Published by Alan Dawson in The Relative Hills of Britain in 1992, the Marilyns quickly attracted the interest of serious baggers. Marilynists' interests are covered by a website, an e-group, a Facebook page, a newsletter (superseded in 2017 by Relative Matters, an annual publication by the Relative Hills Society), an annual meet, and other gatherings. Due to the inaccessibility of the St Kilda sea stacs it took 22 years for the list to be completed, a feat achieved by Rob Woodall and Eddie Dealtry on 13 October 2014. The Marilyn Hall of Fame is open to those who have climbed 600 Marilyns. The Marilyns were extended to Ireland by Clem Clements in The Hewitts and Marilyns of Ireland in 1997.

Marilyns have a drop (minimum descent before ascending to higher ground; also known as relative height or prominence) of at least 150m. They were supplemented in 2007 with the Humps (Hundred Metre Prominence) which reduces the minimum drop to 100m. The list was compiled by Mark Jackson from a large number of sources and originally published online in More Relative Hills of Britain. There are almost 3000 British Humps, including three in the Channel Islands. There are more than 800 Humps in Ireland; the first complete listing was produced by Jim Bloomer in 2011.

Background to the Humps is given in Hill Bagging. By analogy with the Marilyn Hall of Fame, Mark Jackson created the Humps Hall of Fame, requiring 1200 ascents of British Humps.

The Tumps (Thirty & Upward Metre Prominences) comprise all the hills of Britain with 30m or more of drop, with no minimum height. Thus it incorporates a number of other hill lists, and naturally owes its existence to many contributors over several years. The Simms, Deweys, Donald Deweys and Highland Fives comprise the portion of the Tumps above 500 metres. The hills between 300 and 500 metres were first listed by Clem Clements. His work, though never published, was made available to the rhb community, which paved the way for a complete listing of Tumps to be released by Mark Jackson in 2009, upon finishing three years of on-and-off research into the c.8,000 hills below 300 metres. The original list was subsequently revised using data from Myrddyn Phillips' independently compiled lists of English and Welsh hills below 500 metres (the Pedwars, Fours, lower Welsh P30s and subs). The Tumps currently comprise nearly 17,000 hills and have been greeted by a mixture of enthusiastic bagging and the feeling that this is all a bit much. Andrew Tibbetts maintained and improved the list and in December 2011 released an Excel file containing the 10,000-odd hills not present in the DoBIH. This file became the P30 Appendix to the DoBIH in May 2013. It went through two revisions before being brought into the DoBIH in version 14.

Walkers who have climbed 2,000 Tumps are eligible to join the Tump Hall of Fame. The Tump Forum is on Google Groups. The Tump Forum and TumpHoF are maintained by Adrian Rayner. Improvements in online mapping since the original compilation and the availability of LIDAR data are resulting in many additions and other changes to the list. Proposals for new Tumps can be made to the DoBIH editors or on The Tump Forum.

Such is the popularity of the English Lake District that a number of lists have emerged specifically for that region. The best known is the Wainwrights, which was almost certainly not conceived as a list. The Birketts is a more recent listing of Lake District Hills. The Wainwright Outlying Fells and the Birketts were each published as a set of walks rather than a list, but as with the Wainwrights, a tradition of climbing them has developed. The Synges is a longer list of Lakeland hills. The most recent list is the Fellrangers, which resemble an updated Wainwright. The LDWA recognises completions of all these lists except the Synges.

The County Tops of England and Wales were first listed by Moss in 1951. Other listings appeared from 1973 onwards, including coverage of Scotland and Ireland in 1985. In Britain, the frequent local government reorganisations have caused lists based on administrative boundaries to become quickly out of date, and some walkers may prefer to ascend the highest points of the historic counties. Simon Edwardes overhauled the county tops for the Hill Bagging website and produced lists based on both historic and administrative boundaries. These lists are given in the database and are the most up-to-date available. The LDWA records completions of County Tops in England, Wales and Ireland but not Scotland.

A recent phenomenon has been the growing interest in bagging island summits. The Scottish Islands by Hamish Haswell-Smith includes the larger islands (minimum area 40ha) and has been used by some walkers to provide bagging objectives. This is an useful book but is perhaps targeted more at yachtsmen, as the criteria for island status are unintuitive from a hillwalker's perspective (it must be reachable only by boat at all tide states, so Skye is excluded by virtue of the bridge). Rick Livingstone produced an online table of Scottish islands using a 15ha criterion that is more attuned to hillwalkers but seems to be less well known. In October 2014 Alan Holmes published on the rhb group the most comprehensive island list to date. It is targeted specifically at hillwalkers, uses both area and drop criteria, and is the only list to cover the whole of Britain. Baggers are encouraged to report annual totals to Alan Holmes.

The categorisation of mountains worldwide by prominence is well established. For information visit the Topographic Prominence and Europeaklist websites and their associated discussion groups. An early US led initiative was to list hills worldwide with a drop of at least 2000ft (609.6m). Although a register of baggers' totals is maintained by Andy Martin (and by Rob Woodall for British based walkers), the prominence criterion has been superseded by 500m or 600m in countries outside the US. Hills having a drop of at least 500m or 600m can be obtained by a search on drop, or by a sort in the Excel version, and both lists are offered on Hill Bagging. Internationally, 1500m drop has become the accepted standard for the most prominent mountains and the category is known as the Ultras.

In v11.2 we added the Trail 100, a list of 100 hills published in Trail magazine in 2007 which had become popularised by becoming the objective of the WaterAid Trail 100 charity challenge. The list includes one Irish hill, Slieve Donard in the Mournes. The charity event was not repeated after 2008 and 2009, but the list is still referenced in Trail.

Revisions to the lists

Most current lists based on height or prominence criteria have been subject to regular revision. Changes can be broadly classified into the following:
  • Promotions
  • Deletions
  • Replacements
  • Relocations
  • Data changes
The last category comprises changes to primary hill data that would not affect a bagger's ascent records, including small changes in summit location. Such changes are not explicitly mentioned in the database but a change in height, 6-figure GR, drop or col location will trigger a new revision date.

A replacement creates a new hill in the database whereas a relocation does not. With the exception of minor Tumps, most moves of more than 400m will trigger a replacement, as will lesser moves if the summit has a clearly separate identity, or if the former summit is retained as a member of a different list (e.g. the former Marilyn summit of Wansfell is a Birkett).

Our definition of replacement is more liberal than that adopted by the RHB update sheets (in "Hill changes") or the Appendix to the Humps e-book (which requires 30m of drop between the original summit and the replacement). This is necessary in order that a change in location does not invalidate baggers' records, including walkers' logs in Hill Bagging. For example, Botley Hill, which moved by 1km, clearly justified a new record as many baggers had to revisit the hill following the change.

In doubtful cases we will create a new hill if there is a fair chance that a bagger of the former summit would not have visited the new one, recognising that most baggers will make an attempt to locate the highest point when there are plausible alternatives in the vicinity.

For minor Tumps (hills <500m that do not belong to other lists) we have taken a pragmatic approach due to the large number of major relocations we were finding during the data review, a consequence of the age of much of the data. Initially we required a move of at least 5km to merit a replacement. This caused difficulties when the popularity of the Tumps increased, and we now create a replacement for lesser moves where the number of logs on Hill Bagging indicates the hill is fairly popular. When there are only a few logs we do not create a new hill but publicise the move on The Tump Forum, and where possible inform the originators of the logs by email.

A relocation is a significant move (at least 100m, usually more) that is worthy of mention but does not merit a replacement. Relocations are given in the Change Registers, and may also be mentioned in the Comments field.

Change registers

Chronological records of changes (excluding data changes) are given for the following lists.

Munros The Munros 1891-2015
Corbetts The Corbetts 1953-2015
Donalds The Donalds 1953-2015
Grahams Changes to the Grahams
Marilyns Changes to the Marilyns
Humps Changes to the Humps
Simms Changes to the Simms, Murdos, Corbett Tops, Graham Tops and Hewitts
Nuttalls Changes to the Nuttalls
Deweys Changes to the Deweys
Tumps Changes to the Tumps

A change register for the Submarilyns is given on the Relative Hills of Britain site.

Change Control Database
Changes to data in the DoBIH, other than updates from the GPS database, are made through a publicly viewable Change Control Database. Only the database editors can raise change requests, but users may propose changes by email. Changes go through the following stages:
  1. Change Request raised. The status is shown as Requested.
  2. A consultation period during which other editors will check the data and agree the change or make amendments. In the latter case the status will change to Revised. An editor who disputes the change or has reservations (who may be the author) can put it On hold. A change request can be cancelled by the original author. The author will usually agree their own request unless the change is speculative or based on unchecked third party data. The number of editors who have agreed the change following the latest revision is shown after (Agree=) on the summary page.
  3. When two editors have agreed a change, the colour of (Agree=) changes from red to green. At this point the change becomes eligible for application, but the consultation period will remain open until all the editors have had sufficient time to review the change and any debate has ceased.
  4. The status becomes Applied. The changes are applied to Hill Bagging immediately and to the DoBIH in the next release. Any further amendment will require a new change request.
GPS Database

GPS data submitted to the GPS database administrator or logged on Hill Bagging are recorded in an online GPS database that complements the Change Control Database. Submissions postdating the database's introduction in March 2015 have a positive Entry no. in the GPS Data sheet. Earlier submissions imported from the previous offline database can be identified by a negative Entry number. For those entries the corresponding Feature/Observations/Survey entries are taken from the DoBIH as of March 2015, but a full record of the original submissions is held by the database administrator.

All submissions are validated by comparing with existing records and/or checking on maps, as appropriate. Approved entries are fed into Hill Bagging at frequent intervals. Where a hill has existing data, the new measurement may replace the original (usually when a survey has revealed a new location to be higher), otherwise the updated grid reference will be the average of all valid measurements. The xcoord, ycoord, latitude, longitude, GridRefXY fields and derived map links are recalculated from the new GR.

Summits and cols accurately measured by differential GPS equipment are recorded similarly, but a linked Change Control Request is raised to implement height changes and col grid references.


British and Irish hills of any height with a drop of at least 150 metres on all sides. The geographical area includes the Isle of Man and the islands of St Kilda.

A Marilyn Twin Top is a summit of equal height to another Marilyn where the drop between the two is less than 150m and at least 30m. There are two examples, 313 Stob Coire a'Chairn in Scotland and 21168 Knockalla Mountain NE Top in Ireland.

Cruachan Dearg, Meall nan Damh, Sidhean a'Choin Bhain (formerly twin Grahams), Cnoc Coir a'Phuill, Sgurr a'Bhac Chaolais, Middleton Hill, An Stuc, Carn Liath and Saugh Hill were formerly twin Marilyns.

Many hills have alternative summit locations of apparently equal height that fail to qualify as Twin Tops. Examples of such hills feature in the RHB update sheets. For historical reasons a few of these summits have separate entries in the database. For other hills, alternative high points are noted in the Observations or the Comments field. It is left to the walker to decide whether all such points should be visited; on some hills there are many candidates for the highest point and the exercise could degenerate into pedantry.

British and Irish Hills of any height with a drop of at least 100 metres or more on all sides. The name Hump stands for Hundred Metre Prominence. As all Marilyns qualify as Humps, the classification code Hu is only used for non-Marilyns; however all Humps are returned in searches. The geographical area was extended to the Channel Islands in November 2011.

A Twin Hump is defined as a summit of equal height to another Hump where the drop between the two summits is at least 30m but less than 100m.

British hills of any height with at least 30m of drop. The geographical area was extended to the Channel Islands in September 2014.

A Twin Tump is defined as a summit of equal height to another Tump separated by a distance of at least 5km where the drop between the two summits is less than 30m. There is currently one Twin Tump.

Hills in Britain and Ireland at least 600 metres high with a drop of at least 30 metres on all sides. The British Simms is the subset of Tumps in Scotland, England and Wales at least 600m high and was created by its author to replace the Murdos, Corbett Tops, Graham Tops and Hewitts. We have extended the Simms to the Isle of Man (one summit) and Ireland.
Scottish hills at least 3000 feet in height regarded by the SMC as distinct and separate mountains, based on a list originally published in 1891. Subsidiary summits meeting the height criterion are designated Munro Tops; note however that the 'Tops' as defined in Munro's Tables includes the Munros. Summits equivalent to the Munros and Tops in England, Wales and Ireland on the SMC's list are known as Furths.
Scottish hills at least 3000 feet in height with a drop of at least 30 metres on all sides. All Murdos are Munros or Munro Tops but some Munro Tops fail to qualify as Murdos. The list now has "historic" status.
Scottish hills between 2500 and 2999 feet high with a drop of at least 500 feet (152.4m) on all sides.
Corbett Tops
Scottish hills between 2500 and 2999 feet high with a drop of at least 30 metres on all sides. The TACit publication divides them into three sub-categories: Corbetts, Corbett Tops of Munros, and Corbett Tops of Corbetts. The list now has "historic" status.
Scottish hills between 2000 and 2499 feet high with a drop of at least 150 metres on all sides.
Graham Tops
Scottish hills between 2000 and 2499 feet high with a drop of at least 30 metres on all sides. The TACit publication divides them into five sub-categories: Grahams, Graham Tops of Munros, Graham Tops of Corbetts, Graham Tops of Grahams, and Graham Tops of Hewitts (one hill). The list now has "historic" status.
Hills in the Scottish Lowlands at least 2000 feet high. 'Tops' are all elevations with a drop of at least 100 feet (30.48m) on all sides and elevations of sufficient topographical merit with a drop of between 50 and 100 feet. Certain of these are designated 'Hills' according to a formula based on both distance and drop: see the footnote to the second table in Summary of lists.

A related list is Dawson's New Donalds, not given here, in which the qualifying criterion is simplified to 30 metres of drop. The New Donalds are a subset of the Graham Tops. Anyone who has completed the Donalds and Donald Tops will have visited all the New Donalds.

Hills in England, Wales and Ireland at least 2000 feet high with a drop of at least 30 metres on all sides. Although subsumed into the Simms, the list has been retained by its author.
Hills in England and Wales at least 2000 feet high with a drop of at least 15 metres on all sides, as published in The Mountains of England and Wales. The list includes 128 summits that do not qualify as Hewitts. Particularly notable is Pillar Rock as its ascent by the easiest route is a Moderate rock climb or Grade 3 scramble. Many of these additional summits, including Pillar Rock, also feature in Bridge's and Buxton & Lewis's lists. Completions without Pillar Rock are accepted by the LDWA and the Nuttalls, though this is noted in the record.
Hills in Ireland at least 600 metres high with a drop of at least 15 metres on all sides. In 1952 Joss Lynam produced a list of 2000ft summits with 50ft drop with assistance from Rev C R P Vandeleur. Joss Lynam updated a version of this list and published it in a reprint of "Mountaineering in Ireland" by Claude Wall printed in 1976. The metric equivalent was published in 1997. Lynam was actively involved with the list until 2002, thereafter assisting MountainViews with subsequent revisions until his death in 2011.
Hills in Ireland at least 2000 feet high published in The Mountains of Ireland. There is no prominence criterion. 15 Dillons are not Hewitts; 14 have drop <30m, while 20213 Corcog has a 609m spot height (the old 1:10560 map shows 2012ft which converts to 610.6m on the new datum). 12 Hewitts are not Dillons.
Hills in England, Wales and the Isle of Man at least 500m high and below 609.6m with a drop of at least 30m on all sides. Equivalent lists in other geographical areas are the Donald Deweys in the Scottish Lowlands, the Highland Fives in the Scottish Highlands, and the Myrddyn Deweys in Ireland.

The most awkward Dewey is Great Links Tor, which even with the aid of a ladder to gain the crag presents difficulties on wet rock. A completion without Great Links Tor is accepted by the LDWA, though this is noted.

Hills in Ireland at least 500 metres high with a drop of at least 30m on all sides. The list was compiled in 2002 by Simon Stewart in MountainViews and named in 2009. The name comes from the 527m hill which is the County Top for both Laois and Offaly and means, from the Irish, "Height of Ireland". In principle the list amalgamates the Irish Hewitts and Myrddyn Deweys, but there are some differences due to use of a different data source.
Hills in Ireland between 400 and 499.9m high with a drop of at least 30m on all sides as defined by MountainViews, based on a list originally supplied to the Mountaineering Council of Ireland by Myrddyn Phillips. The name comes from Carn Hill, Cnoc an Chairn, "hill of the cairn" in the Sperrins. We have overhauled the data using current and old maps and produced an updated listing identified with the classification code 4. The MountainViews list can be obtained in searches via the code Ca. Differences between the two lists have been tabulated.
Hills in Ireland with height below 400m and a drop of at least 100m on all sides. The list is a subset of the Humps apart from one hill; see discrepancies.
The 214 hills listed in volumes 1-7 of Wainwright's A Pictorial Guide to the Lakeland Fells.
Wainwright Outlying Fells
Hills listed in The Outlying Fells of Lakeland. A previously published source of data is New Combined Indexes to A. Wainwright's Pictorial Guides, John M Turner, Second Edition (1984), Lingdales Press. This list has many inaccuracies. Not least, it is short of two summits explicitly mentioned in Wainwright's book (Caermote Hill, for which the author gives the location of St John's Hill, and the southern summit of Newton Fell) and it also omits the 12 nameless summits.

For a good many hills the summit location is not the highest ground in the vicinity. This is often due to Wainwright's preference for a recognisable feature such as a cairn (which may have disappeared). It is not always straightforward to identify such locations on the map, but most are now resolved following site visits.

The list at the back of Wainwright's book contains 110 named fells and summits. Close inspection shows seven of them to refer to other hills in the list, while Newton Fell has two summits. Thus:

  • Cartmel Fell is the same as Ravens Barrow (page 42)
  • Hollow Moor is the summit of Green Quarter Fell (page 14)
  • Hooker Crag is the summit of Muncaster fell (page 186)
  • Newton Fell includes Newton Fell (North) and Newton Fell (South) (page 53)
  • Potter Fell is the name given to the hill whose summits are Brunt Knotts and Ulgraves (page 8)
  • Lord's Seat is the summit of Whitbarrow (page 36)
  • Williamson's Monument is the same as High Knott (page 18)
  • Woodland Fell is the name of the moor of which Yew Bank and Wool Knott are high points (page 102).
The addition of the 12 nameless summits brings the total number of Wainwright Outlying Fells to 116, 14 more than in Turner's list.
Lake District hills over 1,000ft listed in Bill Birkett's Complete Lakeland Fells.
Lake District hills over 1,000ft published in Tim Synges's The Lakeland Summits (1995, out of print). The book aims to list every significant summit over 300 metres in height within the National Park, including the 214 hills in Wainwright's Pictorial Guides. Distinctions are made between summits above or below 600 metres, between mountains (drop at least 30m) and tops, and between Wainwrights and non-Wainwrights.
Lake District hills included in Mark Richards' Fellranger walking series, a set of eight volumes inspired by the Wainwright guides.
County Tops
The highest point within (or sometimes on) the boundary of each county.

County boundaries change over time. There are different county lists, covering the traditional historic counties and the more recent mixtures of administrative areas.

We provide three separate lists of county tops that we believe are the most commonly used in the pursuit of county top bagging:

  • Historic County tops — traditional list of counties from which people usually take their local cultural identity. In the UK they were never abolished, they just ceased to have administrative function. In the Republic of Ireland, most of the original counties are still real and important.
  • Administrative County tops — incorporating the redrawn administrative boundaries and introduction of Metropolitan Counties in the mid 1970s. These began to be abolished in the 1990s.
  • Current County and Unitary Authority tops — list of Counties, Metropolitan Districts and Unitary Authorities that came into existence in the 1990s, and are still changing. Included are the 11 local government districts of Northern Ireland, together with four City Councils in the Republic of Ireland and three new counties that emerged from the historic 'Dublin'.

For completeness, we have also provided a list of London Borough tops. In terms of administrative tier, these are at the same level as Metropolitan Districts.

Twin tops are listed for some County Tops.

For further information on British county history, see Hill Bagging.

The Significant Islands of Britain are defined as naturally occuring land which at MHWS is completely surrounded by water with either an area of at least 10 hectares within the MHWS contour line or a prominence of at least 30 metres above MSL, or both, all man-made links and structures being discounted. They were researched by Alan Holmes who made his list available to members of the rhb group on 30 October 2014.

The source file divides the SIBs into categories of Main SIBs, B-SIBs and V-SIBs, with a further SIBLET category of islands that do not qualify but may be of interest to trippers. The list offered by the DoBIH contains only the Main SIBs, comprising all islands having an area of at least 30 hectares or a drop of at least 30 metres, excluding sea stacks, as we believe this category is of most interest to baggers. It is also the category relevant to achieving the three levels of membership of the author's SIB Ship. For convenience we drop the "Main" in the database.

Deleted Tops

Sometimes a hill that once appeared on a list is later removed. In the past the most common cause was remapping, though many Munro Tops were deleted on subjective grounds. Since 2006, many deletions have resulted from surveys, and some list authors will not delete a hill without one.

All deleted tops are present in the database, but only deletions in the SMC lists, the Grahams which have been adopted by the SMC but are not owned by them, and deleted Nuttalls are identified by a classification code. For other hill categories, the deletion is usually recorded in the Comments field, at least while the deletion is relatively recent.

The deletion categories are:

  • Deleted Munro Tops (xMT). Includes the deleted Munros, Beinn an Lochain, Sgurr nan Ceannaichean and Beinn a'Chlaidheimh.
  • Deleted Corbetts (xC). Includes Beinn Teallach which was promoted to Munro.
  • Deleted Grahams (xG). Five deletions plus a relocation.
  • Deleted Donald Tops (xDT). Includes the hills in Section 13—Appendix in the 1990 and earlier editions of Munro's Tables, and deleted Donalds (currently only the original location of Meikle Millyea).
  • Deleted Nuttalls (xN). Comprises the summits described as such by the Nuttalls. Most are not true deletions, being candidates for the list that were rejected in advance of the publication.
All deletions at any time in a list's history are identified. Thus the xMT category includes all deletions from 1921 onwards. Details of changes to the SMC lists through the different editions of Munro's Tables are given in the Change registers.


"Subs" are hills in certain prominence based lists falling short on drop by 10m or less. The term originated in the TACit Tables published from 1995 onwards and the principle has been adopted by other list authors. The database lists subs of Marilyns, Humps, Simms, Deweys, Donald Deweys, Myrddyn Deweys, Highland Fives and 490-499m hills.

In the TACit booklets the "sub" categories include hills falling short on height, and there are additional categories for Subcorbetts and Subgrahams. The new definitions appeared in Marhofn in May 2006. The rationale for the change was explained in an rhb group message.

The statistical error associated with heights on OS maps means that some marginals have a non-negligible probability of qualifying for a list. Serious baggers who wish to legitimately claim ascent of all hills meeting the list criteria will need to climb some subs, in addition to hills falling short on height. As a rough guide, for hills whose height and drop have not been accurately measured by surveying you should climb those within 3m of the qualifying height and 6m of drop; for more detailed guidance see section 4 of Accuracy of heights from OS maps. It would be wrong, incidentally, to assume that hills falling short on both height and drop have an insignificant probability of qualification, as the two are correlated. Birks Fell was at one time listed with height 608m and drop 29m.

Description of fields

The headings below are approximately in the order in which the columns appear in the Excel version. There are some presentational differences between the online, Access and Excel/csv versions, but with the exceptions noted below, all data are given in all formats.

The following abbreviations are used when referring to sources:
RHB=The Relative Hills of Britain (including the update sheets); TACit=TACit Tables.

Hill Number
A unique hill identifier to assist with revision and help users raise queries with the authors. The hill number will not be changed during the lifetime of the database unless it is unavoidable; such rare events will be well publicised. To upgrade non-Access versions, sort the old and new releases by hill number and copy and paste your personal ascent records from one to the other. The number of British hills often increases between releases, so paste your British and Irish records separately.
Hill Name
The name(s) by which the hill generally appears in lists and maps. If this varies, we usually prefer the name most compatible with current OS mapping unless another name is particularly well known. Alternative names are given in square brackets. Qualifiers are enclosed in round brackets.

For some multi-topped hills e.g. Liathach and Quinag, the SMC gives both names. For Munros and Corbetts, the Name field gives the two names separated by a hyphen. This allows users to search the database on either name. For Munro Tops we only give the summit name as the range name will appear in the Parent (SMC) field. We have followed the same convention for a few non-SMC hills where the summit has a different name from the hill, usually when the original list gives both e.g. Birnam Hill - King's Seat.

Where a Scots Gaelic name has an apostrophe, our convention is not to use a trailing space. Thus we give Stuc a'Chroin rather than Stuc a' Chroin. However where a' is a contraction (for hills this is usually a contraction of "an") it is correct to insert a space, and OS generally does so. Our usage aligns with RHB, the TACit Tables and most hill names in Munro's Tables, and as we have followed this convention since version 1 we believe that maintaining our current practice is the least confusing for users.

To facilitate searching, accents appearing in Gaelic and Welsh names have been removed.

Irish hill names are taken from MountainViews and Clements' TACit Tables. For British hills we try to include all names appearing in maps and lists that users are likely to search on, even if incorrect.

Parent (SMC)
The hill number and name of the Munro or Donald to which Munro Tops and Donald Tops are linked. For Munro Tops the hierarchy is shown in Munro's Tables. For a few tops the parent is topographically incorrect on current mapping (i.e. not the hill linked by the highest col), e.g. the SMC parent of 527 Carn Lochan is Cairn Gorm rather than Ben Macdui, the parent of 1015 Stob Cadha Gobhlach is Sgurr Fiona instead of Bidein a'Ghlas Thuill, and the parent of 811 Ciste Dhubh is Mam Sodhail not Carn Eighe.

For Donald Tops the 1953, 1969 and 1974 editions of Munro's Tables show the hierarchy correctly but later editions do not. For example, hill 1652 Ben Ever is a top of Ben Cleuch but from 1981 onwards is shown underneath Blairdenon Hill, and hill 1897 Coomb Dodd is shown above rather than below its parent Hillshaw Head. Parents of former Section 13—Appendix hills and the Glen Artney hills that entered the Tables in 1997 have been assigned by us.

Parent (Ma)
The hill number and name of the parent Marilyn of lower prominence hills. In the Excel and csv versions the hill's own number is given for hills that are parents (there are no parents of parents) and '0' indicates a non-Marilyn with no parent. Thus a filter or sort on this column will return a parent (usually first) and all its children. An equivalent facility is provided in Access within the "Parent (Ma)" query, accessible from the Queries menu in the DoBIH_v15.5:Database window.
The RHB/TACit Section number. Sections 1-17 correspond to those in Munro's Tables, enlarged to include lesser hills. In Corbett Tops and Corbetteers (1999) sections 5, 7 and 8 were split for the first time into West (A) and East (B) sections. Section 26 was subsequently split in the Graham Tops booklet. Note that 10A and 10B in Munro's Tables do not correspond to 10A and 10B in RHB.

Sections 43-56 apply to Ireland. We have created Section 57 for the Channel Islands.

Subsequent to the publication of RHB, the boundary between Sections 1 and 26 was moved to follow the course of the Highland Boundary Fault, resulting in some hills being moved from 1B to 26B. The boundary between Sections 10B and 10C was moved eastwards to Loch Blair and the Allt a'Choire Riabhaich. This resulted in Sgurr Mhurlagain being transferred from 10B in RHB to 10C in Corbett Tops and Corbetteers.

Hills duplicated in more than one section of the RHB/TACit Tables, or which could be put in more than one section, have been treated as follows:

Hills on the England-Scotland border
These hills belong to both Section 28B and Section 33 and are searchable in both sections in Hill Bagging and Access. In the Excel and csv versions they have been assigned to Section 33 with the exception of Cairn Hill West Top in 28B. This Donald Top does not appear in English lists (except as a deleted Nuttall, under the name Hangingstone Hill) as the drop before ascending to Cairn Hill is only 5m.

Black Mountain (2242, Wales)
Formerly listed in RHB/TACit as belonging to both England and Wales. With effect from May 2007, Black Mountain is deemed to be in Wales only (32A) for the purposes of lists and databases. Black Mountain is assigned to Wales alone in the Nuttalls' books, as are 2254 Black Mountain South Top and 2262 Pen-y-Garn Fawr which are similarly assigned to Section 32A.

Cuilcagh (20137, Ireland)
Assigned to Section 45D by Clements but is on the International border and the 44A/45D boundary. Cuilcagh is deemed to be in 45D in the Republic of Ireland.

Section name
The name of the RHB/TACit Section.
This field is used principally for the following:
  • Donald Sections in Munro's Tables
  • Wainwright volumes
  • Nuttall book chapters
  • SIB Regions
  • Irish hills
Nuttalls and Donalds area names are used for all hills belonging to those lists. This facilitates comparison with the original lists and will also serve for sorting Wainwrights by volume. For islands, the area name is taken from the maritime Region set out in The Significant Islands of Britain (SIBs) by Alan Holmes. Within the Irish mainland, most hills are given the area names in use by MountainViews. Lower hills not belonging to the relevant hill list may not have had their Area assigned.

A few hills on the Scotland–England border belong to "Cheviots" in the Nuttalls' volume and "Roxburgh and Cheviots" in the Donalds listing in Munro's Tables. This presents a problem with the Excel and csv versions of the database, unless one adopts the clumsy solution of giving each list a separate Area field. Furthermore, in version 12 we wished to assign area names to other Lowland hills and "Roxburgh and Cheviots" is far from ideal. All versions of Munro's Tables prior to 1997 give two areas, "Roxburgh" (section 11) and "Cheviots" (section 12). The SMC amalgamated the two regions when they removed Auchope Cairn and the six unnumbered English tops in 1997, leaving only three hills in total. We decided the simplest solution was to revert to the pre-1997 sections, as "Cheviots" is also the Nuttalls area name. Accordingly, 1906 Cauldcleuch Head is in "Roxburgh", and 1846 Cairn Hill West Top, 2303 Cairn Hill and 2305 Auchope Cairn are in "Cheviots". Note that the There is no conflict between Nuttalls and Wainwrights because the Nuttalls use the Wainwright volume titles.

For Wainwright Outlying Fells we have extended the areas defined in the Pictorial Guides by continuing the Windermere boundary southwards along the River Leven to Greenodd, and from Bassenthwaite Lake north-west along the River Derwent. In England and Wales, Nuttall and Wainwright areas have been assigned to many other hills falling within their boundaries, with Central Wales subdivided into three regions, but this process is incomplete for the Tumps.

In Wales, we needed to define the boundary between the Arans and Berwyns for the hills south of Bala from Rhiwaedog-uwch-afon (3421) in the north to Mynydd Maes-glas (3424) in the south. The easiest solution would be to put them all in the Arans or all in the Berwyns. However in the Nuttalls' book, Moel y Cerrig Duon (2116) belongs to the Arans and Foel y Geifr (2115) and Foel Goch (2123) to the Berwyns. Topographically this is not logical, but the Nuttalls clearly did so because Moel y Cerrig Duon is conveniently included in the same walk as the hills west of the road summit. Our solution is to assign those hills south of Moel y Cerrig Duon and south-west of Lake Vyrnwy to the Arans, and those north of Moel y Cerrig Duon and to the north-east of Lake Vyrnwy in the Berwyns, with the exception of Moel Eunant (3412) which is a satellite of Moel y Cerrig Duon. We feel this is the best we can do without breaking the alignment with the Nuttalls' book.

To divide the Arenigs from the Moelwyns we chose to make the boundary Ffestiniog-B4391-B4407. There are other options but none are demonstrably better. The Moelwyns (as defined by the Nuttalls) span two RHB sections, 30B and 30D.

The island name is used whenever there are two or more Tumps on an island landmass. For islands that are connected to higher ground via a landbridge, when the tide is between MHWS and MLWS, (t) is appended to the island name to indicate 'tidal'. Islands with fewer than two Tumps are in one of four categories: Mono Tump island; Mono Tump island (t); Non Tump island & Non Tump island (t). Irish islands always show the island name. To search on this field in Hill Bagging, list the SIBs and then select Hills by Island from the menu on the left.

Topo Section
The geographical area in Mark Jackson's scheme for Humps and Tumps. In Access, the Topo Section is a searchable option in the Area/Region dropdown box; in the results screen it is given in the bottom row of the Areas/Regions table.
This field is shown in the Excel/csv versions and on Hill Bagging. It gives the Current County or Unitary Authority for the hill. The Access version does not give the county in the search results but offers a search of all hills by county in the Areas/Regions dropdown box.

Membership is calculated using the grid reference and pre-programmed polygons approximating the county boundaries. It may occasionally misassign a hill close to a boundary. Please let us know if you discover an error.

Classification codes
Ma Marilyn 4 400-499m Tump
Hu Hump 3 300-399m Tump (GB)
Sim Simm 2 200-299m Tump (GB)
M Munro 1 100-199m Tump (GB)
MT Munro Top 0 0-99m Tump (GB)
F Furth W Wainwright
C Corbett WO Wainwright Outlying Fell
G Graham B Birkett
D Donald Sy Synge
DT Donald Top Fel Fellranger
Mur Murdo CoH County Top – Historic
CT Corbett Top CoU County Top – Current County and Unitary Authority
GT Graham Top CoA County Top – Administrative
Hew Hewitt CoL County Top – London Borough
N Nuttall SIB Significant Island of Britain
5 Dewey Dil Dillon
5D Donald Dewey A Arderin
5H Highland Five VL Vandeleur-Lynam
prefixes 5M Myrddyn Dewey
s sub O Other list
x deleted Un unclassified
= twin

We identify deletions only for SMC lists and Nuttalls. See Deleted Tops and Subs for details of these categories.

Other searchable categories not shown in the classification field are as follows:

  B&L Buxton & Lewis Tu Tump
Bg Bridge Ca Carn
T100 Trail 100 Bin Binnion

The MT, CT and GT codes exclude Munros, Corbetts and Grahams, respectively.

Most unclassified hills are deletions. The rest comprise hills surveyed as falling short of Nuttall status, and a few that existed on Hill Bagging before the databases were merged in v11.

Height and Grid Reference
Access and Excel have separate fields for 6-figure and 10-figure grid references. As explained below, the former is intended for use with paper maps and the latter for use with walkers' GPS instruments. Hill Bagging has a single field which gives the 10-figure grid reference if one exists and the 6-figure grid reference followed by (est) otherwise.

The treatment of man-made objects on summits is a contentious issue. The database adheres to the protocol described in Summits and Cols.

Great Britain
Much of the data originally entered into the database came from OS 1:10000 paper maps, as used by Dawson in the TACit Tables, with the remainder taken from OS 1:25000 and 1:50000 maps. Since 2012 we have made routine use of the large scale OS mapping on the Geograph website and occasionally the vector maps on the OS OpenData website, both of which show many spot heights absent from the 1:25k and 1:50k maps. This has enabled us to refine many summit and col heights previously estimated by contour interpolation. All spot heights on the original 1:50000 Landranger maps are metric conversions of older imperial heights and they are only slowly being replaced. Many of these old heights were obtained by spirit levelling 100 years or more ago and are more accurate than the air heights on modern metric maps, but their positions on the map may be approximate and, as with air heights, they are not always at the summit. For some hills we have taken levelled heights from old 1:10560 or 1:2500 maps, where necessary adjusting for the change in datum from Liverpool Dock to Newlyn in 1921 (most corrections are <0.3m). All the British hills in the database have been reviewed using the new online mapping resources, the Tumps being completed in March 2015. As the OS are continually revising their maps, further changes are inevitable.

Spot heights often differ between scales. Most discrepancies are 1m. Differences of 3m or more usually correspond to non-identical locations. The error in air heights from photogrammetry is ±3.3m so it does not follow that one measurement is right and another wrong; they are just different estimates of the height. In 2016 we completed a statistical analysis of the accuracy of map heights, using survey data from Alan Dawson and G&J Surveys. The study confirmed a previous finding that there is no difference in the accuracy of spot heights at different map scales, hence no reason to prefer larger scales.

LIDAR data is available in much of England and Wales, and a small part of Scotland. Currently data in upland areas is sparse. LIDAR heights are generally more accurate than those from photogrammetry but are limited by the grid spacing (generally 1m or 2m) and are adversely affected by vegetation. Some heights in the database are taken from LIDAR, mostly for recently investigated hills on the threshold of qualification for a list where such data is available, e.g. additions to the Tumps list. Some decimal heights are given where justified by the nature of the terrain and our ability to identify the corresponding feature on the ground. Decimal heights from LIDAR can be identified by the absence of an entry in the Survey field. A comparison with heights surveyed by G&J Surveys is in progress. Some provisional conclusions are given in this article submitted to Relative Matters magazine.

We now have 10-figure grid references from GPS measurements for most hills in the popular lists. As described below, we use these to derive the 6-figure grid reference. For a growing number of hills we have accurate height measurements from differential GPS. Other published lists may give different data. One reason why grid references can vary is that authors do not measure them in the same way. By convention, a 6-figure OS Grid Reference is the address of the 100m square in which the feature lies. This is given by the co-ordinates of the south-west corner of the square (the same rule applies however many digits you quote). For example, the trig point of Great Shunner Fell is located at SD 84862 97290 so the correct 6-figure grid reference is SD848972. TACit Tables comply with this convention but many list authors round to the nearest 100m instead; in the above example they would give SD849973. Another reason for published grid references not matching ours is that the true summit may not be identified on the map; there are many examples in the database where a spot height or trig pillar is not at the highest point.

Before truncating the entry in the 10-figure grid reference field to create the 6-figure GR, we make a small adjustment to correct for systematic error in the GPS readout (see below). This ensures that 6-figure grid references and xcoord, ycoord values are unbiased relative to the OSGB36 datum.

For Wainwrights the author sometimes gives a summit location that is not the highest point of the fell. This is particularly true of the Outlying Fells. Our policy is to take the location intended by Wainwright. We have followed the same policy with the Birketts. Where there is a conflict between the location implied in the text and the grid reference in Birkett's book we prefer the former, as we understand the GRs were added later by a different author. Any doubtful cases are mentioned in the Comments field.

Metric heights are converted to feet using a factor of 1/0.3048.

Irish data are primarily from 1:50000 2009 digital mapping supplied by OSi and OSNI. Heights surveyed by MountainViews are used where available. Reference to 1:25000 mapping has been possible in the Mournes and MacGillycuddy's Reeks. All these maps offer very few spot heights at cols. Harvey maps have provided some col heights in the Dunkerron Mountains, Maamturks, MacGillycuddy's Reeks, Mangerton, Purple Mountain, Twelve Bens and Dublin/Wicklow areas. For a small number of hills we consulted historic 1:10560 maps to obtain additional heights and to resolve the 21093/21094 twins.

Vertical heights on current mapping are relative to mean sea level at Malin Head. Earlier maps, e.g. the half-inch maps and the 1:63360 District Maps, use the low water mark of the spring tide on 8 April 1837 at Poolbeg Lighthouse, Dublin. The Malin Head datum is approximately 2.7m above the Poolbeg Lighthouse datum.

Channel Islands
Data are taken from Ministry of Defence maps at 1:25000, 1:10560 or 1:10000 scale based largely on 1960s surveys, supplemented by the States of Jersey Official Leisure Map (1:25000) and the States of Guernsey Official Map (1:15000, with 1:10000 coverage of Alderney, Herm, Jethou, Sark and Brecqhou on the reverse). The latter maps are published by Digimap, the official mapping agency for the Channel Islands. The older maps show many more spot heights than the recent maps. Admiralty charts were also consulted. Note that the vertical datum for the latter is MHWS rather than MSL and heights are quoted to the top of buildings rather than the ground.

Grid references are for UTM zone 30U and use the WGS84 datum. This grid is shown on the two "Official" paper maps although it is not the primary grid on the States of Guernsey Official Map, which uses the Guernsey Grid. The grid letters are WA for Alderney and WV for the other islands. Older maps use the ED50 European datum. The two datums give a difference of about 300 metres in grid reference. The extracts from the MoD maps published in the Sunflower guides, and some modern maps such as the 1:12500 International Travel Map of Guernsey and the smaller islands, use the older coordinate system so please bear this in mind when using the data. To avoid potential problems we recommend using latitude/longitude with third party applications.

Garmin GPS instruments use the WGS84 datum by default when set to UTM/UPS grid but return the absolute coordinates (shown in the xcoord, ycoord fields) rather than the lettered GRs. The same is true of GPS Utility. GPS Utility also offers the new Guernsey Grid.

There is also a new Jersey Grid, whose parameters can be found in a web search on "Jersey Transverse Mercator". This grid does not appear on the States of Jersey Official Leisure Map.

We are grateful to David Purchase for researching the maps and providing the data.

Col Height, Col Grid Reference and Drop
Drop, also known as relative height in Britain and Ireland and prominence in the US, is defined as the height difference in metres between the summit and the col connecting the hill to a higher summit. Where there is more than one such col, the highest is chosen.

Cols are usually much less well defined than the summits of hills and therefore six-figure col grid references given in the database generally have an uncertainty of 100m in easting and/or northing. Within much of Ireland there is no data beyond contouring for col position and height. There is, therefore, much greater use of contour interpolation and consequently lower accuracy.

Col heights and drops given to 0.1m are generally from surveys. Col positions given to 8 or 10 figures are from GPS measurements; with the exception of a few obvious locations, these too were generally determined by surveying. Some decimal heights and 8-figure grid references are from LIDAR where justified by the likely accuracy of the data.

As with summits, interference by man, whether by infilling or bridging the original col or creating a new one, necessitates a protocol for dealing with the altered topography. The rules followed by the database team are described in Summits and Cols.

Grid Ref 10
A 10-figure grid reference suitable for input to most hand-held GPS instruments, including all models in the Garmin range.

Except where otherwise indicated, all measurements were obtained on the ground, the majority with hand-held GPS instruments. The error in such measurements has been determined as ±8.5m (three standard deviations) in three independent studies, with the majority accurate to within ±5m of the summit feature. Many are more accurate than this because they are the average of two or more independent readings. Any measurements with survey grade GPS receivers (indicated in the Survey field) will be accurate to 1m.

A comparison of 246 OS measurements of trig points with our GPS measurements in 2006 revealed systematic errors in the GPS data. On average, GPS eastings range from being 7m higher than OS eastings in the westernmost parts of Scotland to 1m lower in the east. GPS northings vary from being 14m lower than OS northings in Northern Scotland to 9m higher in SW England. We are grateful to Darren Parker who had himself discovered this error and researched its cause. We reproduce Darren's explanation below.

The latitude and longitude shown on all Ordnance Survey maps except the most recent are determined with respect to the OSGB36 (Ordnance Survey Great Britain 1936) datum [this changed to ETRS89 in 2015]. The OSGB36 datum is based upon a ground survey performed between 1936 and 1953 and uses the ellipsoid defined by Sir George Airy in 1830. The latitude and longitude can be converted to planar coordinates using a Transverse Mercator projection (once the origin is defined) to give the National Grid references we use. Since the advent of GPS the method of defining the National Grid has changed. It is now defined using the latitude and longitude determined with respect to the ETRS89 datum (which is based upon the WGS84 datum and uses the GRS80 ellipsoid) which are then converted using a transformation known as OSTN15 with respect to OSGB36. The OSTN15 transformation is not a simple transformation defined by equations alone, but because of distortions in the OSGB36 grid, it makes slight shifts in northings and eastings. The grids of northing and easting shifts between ETRS89 and OSGB36 cover Britain with a grid resolution of one kilometre. The shifts of a particular point are then interpolated from this grid. The OSTN15 transformation can be performed online at or using the Grid InQuest software obtainable via the site.

Thus the National Grid is now defined by ETRS89 and the OSTN15 transformation. A good guide to the subject is A guide to coordinate systems in Great Britain. Also available is an Excel spreadsheet with many useful functions for converting from one datum to another.

The OSTN15 transformation replaced an earlier transformation called OSTN02 on 26 August 2016. The difference in positional coordinates is a few centimetres at most so has a negligible effect on the database. Most height changes are also insubstantial, but some heights in NW Scotland and the Scilly Isles have changed by up to 0.3m. This will affect some surveyed heights in the database.

A GPS unit determines the latitude and longitude of its position in the WGS84 datum (which is almost identical to the ETRS89 datum). In order to display this position as a British National Grid reference the GPS unit must perform a transformation. Unfortunately, the transformation equations stored in the unit are not as accurate as the OSTN15 transformation. Garmin and Magellan units use a transformation known as a Molodensky transformation (the equations and required parameters can be found in "Department of Defense World Geodetic System 1984 - Its Definition and Relationship with Local Geodetic Systems, NIMA TR8350.2, 3rd Edition, Amendment 1, 3 Jan 2000"). This leads to the discrepancies highlighted above. The transformations used by other manufacturers have not been investigated.

A number of strategies are available to remove the errors introduced by the Molodensky transformation. GPS waypoints can be downloaded to a computer using free or commercial software and the WGS84 latitude and longitude extracted. These can then be converted to British National Grid references using Grid InQuest or the online program, both of which have a batch mode facility. Alternatively, if the British National Grid references have been copied from the GPS screen, these can be converted back into WGS84 latitude and longitude values using the Molodensky transformation equations directly or by using either of the free programs Geotrans or GPS Utility. As before, these can then be converted to British National Grid references using Grid InQuest. All three packages have a batch conversion facility.

When entering position coordinates of a location into a GPS, one has to bear in mind the source of the coordinates. If a grid reference has been read from the screen of a GPS instrument, then entering the grid reference into another GPS instrument using its own input screen will result in a point in the correct location (even though the grid reference may be incorrect). However, if the position coordinates are uploaded using computer software, the coordinates should be in the form of WGS84 latitude and longitude values.

Since we presume most users will be using 10-figure grid references for input to GPS instruments, we have not corrected the GPS measurements for the systematic error described above. Some ten-figure grid references were obtained with survey grade GPS receivers (see survey), and these instruments report accurate grid references to the OSGB36 standard. To align with the other data, the systematic error of the Garmin/Magellan instruments has been introduced into the grid reference using the reverse of the correction procedure described above.

Grid references from Satmap GPS instruments do not have the systematic error of the Garmin and Magellan instruments as they use the OSTN15 or OSTN02 transformation or a better approximation to it. If you have a Satmap Active model you will obtain more accurate waypoints if you take the coordinates from the lat/long or GridRefXY fields.

Because 6-figure grid references are usually used with maps, we correct the 10-figure grid references for the GPS error before truncating them to derive the figure for the Grid Reference field. This is done automatically when applying a GPS update to the database by means of an Access/VBA application that successively transforms the data to WGS84 and OSGB36 using components of GPS Utility and Grid InQuest. This operation also populates the Latitude and Longitude, xcoord, ycoord and GridrefXY fields.

The Irish National Grid was formerly defined by the Airy Modified Ellipsoid and the Ireland 65 map datum, which uses a transverse mercator projection. It is now defined with respect to the ETRF89 geoid and Irish Transverse Mercator. The transformation from latitude/longitude uses the OSi/OSNI Polynomial Transformation, which can be performed by GridInquest or online. Irish GPS measurements undergo the correction procedure outlined above for British data. OSi and OSNI changed the geoid model on 26 August 2016 in parallel with OS. Unlike OS they did not change the horizonal transformation, but heights have changed by up to 0.2m in the west of Ireland.

The feature to which the 10-figure grid reference refers is identified in the Feature field. Alternative candidates for the summit and other features of interest are given in the Observations field. Many GPS data contributors submit measurements for other locations that are not summit contenders. Only a few of these are entered in the DoBIH, but all are recorded in the GPS database from which the entries in the DoBIH are derived.

Submitting 10-figure grid references
It is our aim to obtain GPS-measured ten-figure grid references for as many hills as possible. Please contact us if you would like to contribute. Each entry in the GPS database is credited to the person who made it. Please record: name and number of hill, ten-figure grid reference, height as given by GPS, precision of GPS at time of measurement (if known), the feature the measurement refers to (e.g. cairn), your name and the date on which the measurement was made. To prevent transcription errors it is helpful if you can use this Excel template; however we will accept data in any format. You can also submit your data on Hill Bagging if you are a registered user. Your GPS should be set up according to the manufacturer's instructions using British Grid as the position format and Ordnance Survey GB as the map datum. For Ireland, use Irish Grid and Ireland 1965, and for the Channel Islands, UTM/UPS and WGS84. GPS instruments take a few minutes to stabilise and give reliable data, particularly older models that do not receive the GLONASS satellites. Try to remember to switch on your GPS a few minutes before reaching the summit and try to leave the unit for at least five minutes to settle once it has locked on to satellites before taking a reading.

Some newer GPS instruments, e.g. Garmin Oregon and Montana models, have a built-in barometric altimeter and use this by default to record height in preference to the height measurement of the GPS. Please record the GPS height and not the height from the barometric altimeter.

If you have a Satmap Active GPS, please submit your measurements as lat/long. These instruments use a different transformation to convert lat/long to grid reference from Garmin models so we have to process the data differently. Our preferred format is decimal with a minus sign for W, e.g. 57.13781 -3.58466.

Please send your GPS data to for British hills and to for Irish hills. We welcome your input.

We do not publish 10-figure grid references from maps because spot heights and trig points are frequently not at the summit.

For a list of those who have contributed data, please see acknowledgements.

The feature on or around the summit to which the 10 figure grid reference refers. The summit area may be adorned with several objects (trig point, cairn, wind-shelter, fence etc.) and the resolution of the GPS is usually sufficient to be able to distinguish the positions of these features. Note that a cairn or trig point is not always at the highest point of the hill, which may itself be featureless. Consequently, the Feature field may contain the entry 'no feature' even though a cairn, trig point or other feature is in the vicinity. This is particularly likely for hills that have been surveyed. In such cases the Observations field is often used to record the summit position relative to more obvious features such as cairns for which ten figure grid references are also frequently recorded.

Where no survey equipment has been employed, we do not claim that the feature and its accompanying ten-figure grid reference represents the true summit of the hill; it is the best endeavour of the contributor who submits the data.

This field contains information that supplements the Feature field. Most often it gives ten-figure grid references for other high points, either alternative summit locations or features that have been surveyed as lower.
This field records whether any of the summit position, height, drop, col height or col position were determined by surveying, and if so the instrument(s) used. Data given to one or more decimal places are usually from survey measurements. Thus for hill 2051 Mynydd y Cwm the Survey field contains "Leica NA730/Leica 530" showing that these instruments were used in the determination of col position, col height, summit position and summit height; the respective fields contain entries to 0.1m. We include "LIDAR" in the Survey field only if the data were used in conjunction with an instrumental survey, e.g. on 19212 Currock Hill and 18430 Warren Hill.

The protocol used by the DoBIH for defining heights and positions in the presence of water features, moveable rocks, man-made structures, or when ground has otherwise been disturbed by man, is explained in Summits and Cols. This protocol is also followed by the MountainViews surveyors in Ireland.

The most basic surveying tool we use is an Abney level which has a practical resolution of about 50cm of height per 100m of distance. This is sufficient to enable the true summit position of most hills to be determined, although the relatively poor resolution only permits height differences to be determined semi-quantitatively. Some summits in the vicinity of trig pillars were levelled to the flush bracket by Abney Level; the height difference from the figure in the OS Legacy Database was used to estimate the summit height. Our guide to choosing, calibrating and operating an Abney Level may be helpful to walkers using these instruments. Recently some contributors have acquired Hand levels with a x2 magnification manufactured by Kuker-Ranken or Seco. Our initial evaluation suggests these levels can give a resolution of 20-30cm per 100m distance in favourable conditions, the stability of the level being critical.

For hills where greater resolution is required, the survey team initially employed a Leica Runner 20 Automatic level, and subsequently a Leica NA730 Automatic level, purchased by a DoBIH editor. The Leica Runner has a x20 telescope and gives a resolution of about 1cm of height per 100m of distance, while the NA730 boasts a x30 telescope and correspondingly higher resolution of about 0.5cm of height per 100m of distance. An Abney level is a small device weighing about 150g which easily packs into a rucksack. An automatic level, e.g. a Leica Runner or a Leica NA730, weighs about 1500g, occupies significant space in a daysack and also requires a sturdy tripod.

The survey team also has access to a Leica Disto A8 laser measurer that measures both distances and angles. This was used to survey Castell y Gwynt and the depth of the railway cuttings at the cols of Lambrigg Fell and Milk Hill.

Optical levels are of limited use for determination of absolute height because they require a suitable datum e.g. a trig point of similar altitude that can be sighted directly or indirectly. Hills surveyed by this means include Birks Fell, Cracoe Fell and Great Yarlside. Optical levels enable accurate measurements of drop by differential levelling, and this has enabled us to determine the status of hills on the borderline of inclusion in the Nuttalls' and Dewey's lists. Because of the number of staff placements required and the time this would take, the technique is impractical for determining Marilyn status, where the drop is 150m. Differential GPS does not have these limitations, enabling accurate determination of height and drop for most hills. In 2009 a Leica 530 survey-grade GPS system was acquired, which was used on all surveys requiring accurate determination of summit height and for most measurements of drop. Prior to this purchase we surveyed Craig Fach and Mynydd Graig Goch by differential GPS in collaboration with Leica Geosystems. Many hills have had their drop measured by both optical levelling and differential GPS. Agreement has invariably been excellent, but levelling is more accurate.

In October 2012 G&J Surveys purchased a Leica Viva GS15 Professional GPS receiver to replace the Leica 530. The precision of the two instruments is comparable and dependent on the data collection time. For 30 minutes data collection this is about ±0.07m, for one hour's data collection about ±0.06m and for 2 hours data collection about ±0.05m. G&J Surveys generally uses 1 hour's data collection, but 2 hours when heights are to be ratified by Ordnance Survey. Where the new instrument has been used the Survey field contains the entry "Leica GS15".

The overall precision of a measurement is also dependent on the correct location of the col and/or summit. G&J Surveys does this with level and staff and in the case of cols takes measurements on a grid of flags laid out over the col area in order to determine its topography. This enables them to locate the position of the col as accurately as possible. For most of their surveys the overall uncertainty in summit height is ±0.1m and of col height ±0.15m (3sd), but the nature of the terrain (see below) is critical. For more information see the survey report for the particular hill.

During 2012 a Leica RX1250 GPS receiver was acquired by Alan Dawson and many of his survey results are recorded in the DoBIH. The instrument's precision is the same as that of the GS15, but until late 2012 when an Abney level and later a Leica Disto D510 laser level were purchased, no instrumental method was used to locate a summit or col. These surveys are identified by "Leica RX1250" in the Survey field. Some reports may be found at

In December 2013 Myrddyn Phillips purchased a Trimble GeoXH 6000 receiver. His survey results up to the end of 2015 are included in the database. The precision of this instrument is currently ±0.3m, poorer than the Leica instruments, but the Trimble has greater portability and requires much shorter data collection times. No instrumental method is used for locating a summit or col. These surveys are identified by "Trimble GeoXH 6000" in the Survey field (excluding those measured with MountainViews in August 2013 and some surveys of northern hills by Alan Dawson, see below). Details of the surveys are given in A comparison of measurements made by the Trimble and the Leica GS15 is available in a spreadsheet on the above site. More recently Alan Dawson obtained a Trimble GeoXH 6000 and from April 2016 a few measurements with this instrument are recorded in the database.

In Ireland, MountainViews has acquired a Trimble GeoXH 6000 receiver. As of v15.5, 129 hills quote heights obtained with their instrument, identified by "Trimble GeoXH 6000" in the Survey field. A number of surveys were carried out jointly with MountainViews at the end of August 2013 to compare measurements made with their instrument and ours. The results are reported in A performance evaluation – Trimble GeoXH 6000 vs. Leica Viva GS15 Professional. Some further comparisons were made in Ireland in September 2015 and agreement was again very good.

When surveying summits and more particularly cols, the overall accuracy of the measurements is more often determined by the nature of the terrain than by the limitations of the equipment. If a summit is covered with thick tussock grass or heather, it can be difficult to establish the summit location even using automatic level and staff. In a very few surveys we have determined, from variation in level and staff measurements, uncertainties of up to ±0.2m. The situation is worse for cols of complex topography and thickly vegetated terrain, when uncertainties could reach ±0.5m on occasion. Clearly, without instrumentation to locate summits and cols, it is sometimes impossible to produce satisfactory estimates of the uncertainty in the measurements, which could exceed the above figures.

The heights of Foinaven and Beinn Dearg were measured by a survey company, CMCR, for The Munro Society.

Reports by G&J Surveys can be read on Hill Bagging. For details of the surveying methods and more detailed discussion of the accuracy of the measurements, see The Accuracy of The Munro Society Heighting Surveys and Determination of the Random Error in Level and Staff Measurements. Video footage of some of the surveys can be viewed at G&J Surveys.

Where an instrument was not required to determine the summit position and no other survey has been conducted, 'obvious summit' is recorded in the Survey field. A blank field denotes that the hill has not been surveyed.

County Top
In Excel/csv, the relevant county or counties for a County Top.
The date of the last change to the primary data: classification, 6-figure GR, height, drop and col location.
Significant revisions, alternative summit locations not from site visits, and other explanatory notes. We do not comment on revisions of a routine nature.
Link to an OS 1:50000 map on The next zoom setting gives a 1:25000 map. For hills lacking a 10-figure grid reference the arrow will point to the SW corner of the 100m square defined by the 6-figure GR.

In Ireland this field links to the OSi map viewer. Unfortunately the Wind Report overlay, which showed more detail than Street Map, has been removed. In Northern Ireland the only detailed mapping is offered by the Historic options.

Link to the hill's page in Hill Bagging.
For British hills, link to Geograph mapping. Currently this links to the Experimental Coverage Map, which can be zoomed to 1:50k, 1:25k, and a larger scale. The pop-up window linked in previous releases can be obtained by clicking on the link to the right of "Map Center" and then clicking inside the map in the new page. The two largest scales lost detail a few years ago but this has now reappeared.

For Irish hills, link to the hill's page on MountainViews. For hills not featured on MountainViews, the field links to Geograph but its functionality is limited.

We have found a bug in Geograph that can cause the coordinates to be displayed incorrectly in the pop-up window linked in previous releases. The grid reference readout is sometimes at some distance from the cursor position. From reports to date the error appears to be always in the northing, the displacement in metres being scale dependent. So positioning the cursor on an intersection of grid lines e.g. SD 38000 97000 can give a readout SD 38000 96957 on the 1:25k map. A similar error occurs in the position of the blue circle. On clicking inside the map, the green circle is displaced relative to the cursor. The problem appears to be unrelated to the operating system and can come and go on the same hardware. We are not aware of any problem with the Experimental Coverage Map.

xcoord, ycoord
Absolute grid reference (eastings, northings) in metres relative to the Ordnance Survey National Grid origin, Irish Ordnance Survey National Grid origin, or UTM zone 30 origin as appropriate. Required by some GIS software e.g. ArcView and MapInfo. Not available on Hill Bagging except via the Geograph link, where it is shown on moving the cursor inside the zoomable map.
Latitude, Longitude
WGS84 coordinates calculated from the xcoord, ycoord values. The accuracy will depend on the source of the measurement. Use of latitude/longitude gives compatibility across Britain, Ireland and the Channel Islands. Not available in Hill Bagging except by showing the map and moving the cursor to the triangle marker.
True 10-figure grid reference, for use with maps. Exactly equivalent to xcoord, ycoord.

For hills having an entry in the Grid Ref 10 field, the systematic component of the GPS error has been removed. For hills lacking a 10-figure GR, the 6-figure GR is converted to a 10-figure GR by padding with zeros. Used for generating the Geograph map links, which unlike Streetmap do not accept xcoord/ycoord or lat/long. Not shown in the search results table or in Hill Bagging, but available in the hills table of the Access database and in the Excel and csv versions.

A numeric version of Section given in the Excel and csv versions.
For Irish hills, the MountainViews hill number, as given in the hill page's URL on the MountainViews website which takes the form where xxxx is MVNumber. Shown in the Excel and csv versions, and in the MVNumbers query in Access.

Changes and issues

Background on hill classification changes and issues referenced in the Comments field of the database or of general interest is given below. Hills are listed in Section order.
Beinn a'Chroin (2925, 1C), Beinn a'Chroin East Top (36, 1C) and Beinn a'Chroin West Top (37, 1C)
All editions of Munro's Tables give hill 36 as the Munro and hill 37 (West Top) as a Munro Top. Research by Richard Webb suggested that a summit 200m east of the West Top was higher than the Munro as long ago as 1983. The latest 1:50000 and 1:25000 maps both show a 942m spot height at NN387185, which the OS has indicated is rounded from 941.5m. For some years the SMC has given this summit (hill 2925) as the Munro on its website and CD. The online version of Munro's Tables does not list Munro Tops, but in view of the considerable separation and drop between the two summits we have assumed hill 36 will become a Munro Top. A survey has confirmed that hill 2925 is higher.

Munro's Tables gives the West Top as the cairned point at NN385185, hill 37. It likely to be deleted in the next edition as it is only 200m from hill 2925 with ca.10m of drop.

To summarise, the current status of the Beinn a'Chroin tops is as follows:

  • hill 36, NN394186, 940.1m
    formerly the Munro, Beinn a'Chroin in Munro's Tables (1997); expected to become a Munro Top with probable name East Top in the next edition
  • hill 37, NN385185, 938m
    listed as a Munro Top, Beinn a'Chroin West Top in Munro's Tables (1997); likely to be deleted in the next edition, but no indication yet from the SMC
  • hill 2925, NN387185, 941.4m
    new position of the Munro
An Dun (399/400, 5B)
Both the Marilyn and the Corbett were originally at the southern top. The Marilyn moved to the northern top in 1995 following the appearance of an 827m spot height on OS Maps, 1m higher than the south top. The 1997 edition of Munro's Tables made the same change. However the more recent online version of Munro's Tables reverted to the southern top. A line survey by G&J Surveys in 2012 found the southern top to be slightly higher but the estimated height difference of 3cm was within the measurement error associated with finding the highest points on the ground. Ordnance Survey accepted the result and put an 827m spot on each summit. A GNSS survey by Alan Dawson in 2017 drew the same conclusion, following which the Marilyn summit was relocated to the southern top. Both surveyors agree that the two summits should be regarded as being of equal height.
Fiacaill na Leth-choin (560, 8A)
This top first appeared in the 1921 edition of Munro's Tables and is described as being 2/3 mile WNW of Cairn Lochan. The 1900 1" map, and all later 1" maps, show a ring contour at NH9703 and this grid reference is given in the 1969 Tables. Although the mapping is incorrect (a consequence of the contours being surveyed by the unreliable water levelling technique), it nevertheless points to a location near the end of the ridge at NH975028 being the intended summit in Munro's Tables from 1921 to 1969. This was revised to the position of the 1083m spot height at NH 975024 in the 1974 Tables. The 1869 and 1902 6" maps have a 3556ft spot height here, but it was not used in the 1921 Tables which gives "3550 ap." and credits Sir Hugh Munro.
Carn Liath (595, 8B) and Creag an Dail Bheag (596, 8B)
Both summits were for a long time marked as 862m on OS maps. Creag an Dail Bheag was the Corbett up to 1984 and Carn Liath from 1990. Alan Dawson surveyed both hills in September 2013 and found Creag an Dail Bheag was 1.5m higher. Accordingly, the Marilyn moved to Creag an Dail Bheag. Ordnance Survey subsequently processed the raw data and obtained 861.47m for Carn Liath and 863.02m for Creag an Dail Bheag, the accuracy being estimated as ±0.05m. They furthermore indicated that the mapping would be changed to show 861 and 863 respectively and that the spelling Creag an Dail Bheag would be shown at all scales. The SMC moved the Corbett back to Creag an Dail Bheag in 2015.
Corrieyairack Hill (632, 9B)
There has been some controversy concerning the location and height of the summit of this former Corbett. The Corbett Tops booklet states that the new summit height is taken from the 1:10000 map and is 1m higher than the old top. We have confirmed this with an Abney level, which showed that the new summit position is 1.5m higher than the old. For the OS's reply to a query see Marhofn 106.
Beinn a'Chaorainn (663/665, 9C)
Older 1:50000 maps show the South Top at 1050m, higher than the Munro/Marilyn at 1049m. Following enquiries in August 2001, the OS admitted that "something odd seems to have happened" and re-heighted both peaks. Both 1:25k and 1:50k maps now show the Munro/Marilyn as 1052m and the South Top as 1049m. However the large scale map on Geograph spots both summits at 1049m.
The Saddle [Trig Point] (686, 10A) and The Saddle (688, 10A)
Hill 688 has always been the accepted summit of the Munro. Munro's Tables give a height of 3317ft from 1891 to 1969, 3314ft in 1974 and 1010m from 1981 onwards. The trig point was a Munro Top between 1981 and 1990 and was listed as 1010m. There also appears a rather optimistic footnote from 1981 onwards "Observation on the ground gives the impression that the main summit of The Saddle is slightly higher that the Trig Point".

The current 1:25000 map gives a height of 1011m for the rocks near the trig pillar and 1010m for the Munro, resulting in the Marilyn being moved to hill 686 in August 2013. It reverted to hill 688 after that summit was surveyed as 0.3m higher in September 2014.

The Saddle West Top (696, 10A)
There are two high points at NG928128 and NG929128. From 1891 to 1969 the summit is described in Munro's Tables as being ½ mile WSW of The Saddle which is midway between them. However its height is given as 3196ft (974m) and on the 1876 6" map this spot height is shown and corresponds to NG929128 (the 1902 map is identical). The same grid reference and height (974m) are given in the 1974 Tables. In the 1981–1990 Tables the summit position is moved to the western high point at NG928128 and the height is given as c968m, as suggested by the contemporary Landranger but lower than the old levelled height. Geograph and the OS vector map give a 974m spot at the original location. The Top was deleted in 1997.
The Saddle North Top [1921: Sgurr na Creige] (706, 10A)
The intended summit is uncertain. It is described in all editions of Munro's Tables as being half a mile north of the summit and about 3100ft in height (the first edition says over 3000ft). In the 1932 SMC Guidebook for The Western Highlands, though, Stob na Creige is described as being about 2850ft in height. A visit showed Stob na Creige to be a short undulating ridge with three small tops, the drop between each of these being no more than 5m or so. The furthest from the Munro is 867m or 2844ft and is 1.1km or 0.68 mile along the ridge from the summit. The next top is 926m or 3038ft at 0.7km or 0.44 mile from the summit, and the next after that is 933m or 3061ft at NG 93570 13715, 0.6km or 0.37 mile from the summit. There are two other significant bumps closer to the summit. We give the 926m feature in the database as it seems to best fit the description.
Buidhe Bheinn (713/715, 10A) and Sgurr a'Bhac Chaolais (716, 10A)
Munro's Tables lists Buidhe Bheinn as the Corbett from 1953 to 1974, Sgurr a'Bhac Chaolais from 1980 to 1990, and both hills as Corbetts in 1997 despite the drop between the two being less than 500 feet. However the location of Buidhe Bheinn was mistakenly assigned to the west top at NG956087 (hill 715), whose height is given as 879m on OS maps. The 2002 edition of the SMC guide to the Corbetts corrected the location to NG963090 (hill 713), and this GR is now shown in the SMC's online Table. Accordingly, we have classified hill 715 as a deleted Corbett.

Following a survey which found Buidhe Bheinn to be 29cm higher, the SMC demoted Sgurr a'Bhac Chaolais on 3 November 2012. Thus Buidhe Bheinn is now the sole Corbett. The following day it was reported on the rhb group that the Marilyn pair had been de-twinned and the Marilyn moved from Sgurr a'Bhac Chaolais to Buidhe Bheinn.

Beinn Aoidhdailean (4267, 10A) and Sgurr Mor Near West Top (4270, 10A)
The first Graham Tops (now Simms) to be added following the publication of the Graham Tops booklet. Beinn Aoidhdailean was announced in The Angry Corrie (TAC66) in December 2005. Topographical mapping suggests the 607m spot in the col area on the 1:25k map is a protuberance and the ground drops 5m to the south. A survey in May 2015 confirmed its status.

There is no 610m contour surrounding Sgurr Mor Near West Top (originally Druim Fada point 615m, revised to point 614m), which was added in July 2007 on the basis of a drop of 32m measured by altimeter. Its status was confirmed by a survey in May 2015 which gave height 614.1m, drop 31.4m. The same survey gave hill 4272 as 614.0m, drop 32.7m and confirmed our assignation of the cols east and west of hill 4270, both spotted as 1909ft on old 6" maps.

Sgurr nan Ceannaichean (900, 12A)
Reclassified from Munro to Corbett following surveys carried out for The Munro Society. The news was announced at a press conference on 10 September 2009. Rab Anderson of the SMC was present and confirmed that Munro's Tables were changed with immediate effect. The SMC made the following statement:

Following confirmation that the Ordnance Survey will adopt the height information from the recent surveys carried out by the Munro Society, the Scottish Mountaineering Club (SMC) can confirm that it will amend the official list of Munros (Munro's Tables®), which it maintains, to show that Sgurr nan Ceannaichean (913m) is now no longer a Munro. This change brings the number of separate summits in former SMC member Sir Hugh Munro's list of 3000 foot peaks to 283. Sgurr nan Ceannaichean will be added to Corbett's Tables which the SMC also maintains and all future SMC publications will show these changes. The SMC is grateful to the Munro Society for its efforts and for bringing this revised height information to its attention.

Surveys of Ben Vane (915.8m), Beinn Teallach (914.6m) and Sgurr a'Choire-bheithe (913.3m) confirmed the status quo.

Beinn a'Chlaidheimh (1024, 14A)
On 4 July 2011 the height of Beinn a'Chlaidheimh was measured by G&J Surveys as part of a project for The Munro Society. A 3 hour dataset was sent to Ordnance Survey for processing who obtained a height of 913.96m. The Munro Society announced the result at a press conference on 9 August 2011. The new height indicated that Beinn a'Chlaidheimh should be reclassified from a Munro to a Corbett. In response the SMC said in a press release, The Scottish Mountaineering Club has been notified of these survey results and has undertaken to consider the implications for Munro's and Corbett's tables when the Ordnance Survey update its map of the area. OS Get-a-map has shown a 914m spot height since 29 November 2011. The SMC finally accepted the reclassification on 6 September 2012. The news was first reported in Grough.
Beinn Dearg North Top (3267, 15A)
Added to the Corbett Tops after publication of Corbett Tops and Corbetteers but demoted when the height was reduced to the 884m spot on the 1:25000 map. The 1:50000 map still shows 886m. The col height is taken from the 2811ft spot on the 1:10560 map although the map suggests a better estimate might be 855m, which would increase the drop to 29m. Pending a survey it remains a Subsimm.
Foinaven (1124, 16B)
There had been speculation for many years that the height of this hill might reach 3000ft. Older 1:50000 maps show a spot height of 908m at NC316507, a conversion of an imperial height. It was eventually replaced by the 914m figure from the metric survey, though the spot is at NC315507 on the 1:10000 metric map. Anecdotally, the 1:25000 map briefly gave the height as 915m, later changed to 914m at NC316507. In response to an enquiry from the SMC in 1990, the OS confirmed the height as 914m but quoted a range of 913.8-915.2m including measurement error. The midpoint of this range is 914.5m, suggesting that the hill was more likely to be a Munro than a Corbett. The confusion was compounded by the spot height on the 1:25000 map being within the small 910m contour to the east of the ridge, rather than at the cairn inside the much larger 910m contour to the west which ground observation suggested was about 3m higher.

In 2007 The Munro Society commissioned a survey of Foinaven. The summit height, ratified by the OS, was reported as 911.0m. The new height is shown on the current 1:25000 map. A survey of Beinn Dearg (hill 970) commissioned at the same time confirmed the hill's Corbett status, the measured 913.7m equating to the old levelled height of 2998ft.

Knight's Peak (1261, 17B)
Knight's Peak was controversially promoted to Munro Top in 1997 on the basis of an altimeter measurement. The accuracy of the published 914m height (by implication 914.4 or 914.5m) was openly questioned in parts of the hillwalking community, and appeared to be contradicted by Harvey's estimated 911m and a figure of 2994ft on the 1965 1:10560 sheet. In August 2001 the OS disclosed that it holds an unpublished air survey height of 912m for Knight's Peak. A spot height of 912m also appeared on Land-Form PROFILE, the OS 1:10000 digital height product. The OS height was adopted for the TACit Tables, so Knight's Peak became a 912m Corbett Top in 1999.

Then in August 2006 Ken Stewart obtained a new height of 914.95 ± 0.5m from the OS, derived from high order photogrammetry and GPS. On enquiring about the methodology, the OS replied The photo model was controlled using sub 0.1m accuracy GPS (i.e. points on the ground were fixed that could be identified on the imagery - GPS was not taken to the summit). The accuracy of the imagery heighting using this method is quoted as ±0.5m for the Z (height) value. Not everyone accepted the data as conclusive (see issue 69 of The Angry Corrie). Knight's Peak was eventually reclassified from Corbett Top to Murdo in 2010, but doubts remained.

The issue was finally settled by a survey carried out on 13 September 2013 by G&J Surveys in conjunction with the SMC and The Munro Society. The higher of the two summit peaks is 914.24m and the lower one 914.16m. The deletion of the Munro Top was announced on 13 November on BBC Scotland.

Meikle Millyea (1693/1694, 27B)
The 1860 6-inch map shows a 2446ft (746m) triangulation station at the northern summit (hill 1694) and a 2455ft (748m) spot about 400m to the south-west (hill 1693). The latter position is also spotted 3m higher on the Harvey 1:40000 map. The TACit publications have given the southern location since 1995. The 2015 SMC guidebook The Grahams & the Donalds retained the trig point while recommending that walkers also visit the southern summit. However a survey subsequently conducted by G&J Surveys for the SMC has confirmed that the south-west top is indeed the higher, a result validated by Ordnance Survey. Future SMC publications will reflect this and give the south-west top as the Donald.
Troweir Hill (1734, 27B) and Saugh Hill (5636, 27B)
Saugh Hill became a twin Marilyn of 1734 Troweir Hill on 17 June 2011 following an examination of old maps. Both hills have a spot height of 296m at 1:50k. Large scale 19th century maps give levelled heights at the cairn and the tumulus with Saugh Hill 0.4m higher. A survey by Alan Dawson in July 2014 obtained a height of 295.6m for both summits but a drop of only 149.3. Accordingly, Troweir Hill was deleted from the Marilyns and Saugh Hill ceased to be a twin Marilyn although it remains a twin Hump.
Craig Fach (2032, 30B) and Mynydd Graig Goch (2033, 30B)
These hills, both with spot heights of 609m on contemporary OS maps, were surveyed on 11 August 2008 by our survey team in collaboration with Leica Geosystems. Craig Fach's Dewey status was confirmed but Mynydd Graig Goch was shown to be over 2000ft high, making the hill a Hewitt and Nuttall. The event is described in the press release. Many readers will be aware of the events that followed. The team had planned an announcement at Snowdonia Parks centre (Plas Tan-y-Bwlch) but had not achieved much success in getting the press to attend. Then the BBC got hold of the story and everything mushroomed, with coverage on Radio 4, BBC TV and ITV on Friday 19 September and in the national newspapers the following morning. The promotion of Mynydd Graig Goch to "mountain" status may have provided the whimsical note that captured the nation's interest, but a contributory factor might have been the relief afforded from the relentless stream of financial and economic bad news.
Mynydd y Cwm (2051, 30C)
New Marilyn announced on 16 April 2009. The measured drop of 150.00 ± 0.2m sparked some debate as to whether the promotion was justified. However all hill lists, whether the authors recognise it or not, are based on the premise that a hill belongs if it has a 50% or greater probability of meeting the criterion.
Mynydd Ceiswyn (3431, 30F) and Domen-ddu (3466, 31B)
Added to the original list of 500m summits (with Great Yarlside) by Michael Dewey, but challenged on the rhb group by Rob Woodall and others. These hills, together with Great Yarlside, were promoted on the basis of measurements on walkers' GPS instruments, which lack sufficient accuracy for this type of work. All three hills have since been shown by accurate levelling to lack the required drop. Details can be found in Survey Reports. A number of other Deweys, mostly hills added after publication of the original list, have been demoted after surveying. See the Dewey change register for a full list of changes.
Rhiw Gwraidd (2196/2197, 31B)
A levelling survey in 2006 was unable to resolve the summit location as the height difference was within the measurement error. A second survey in June 2010, using equipment capable of higher resolution, found the east top to be 7cm higher. Accordingly hill 2197, formerly an alternative summit mentioned in the rhb update sheet, is now the Marilyn. Hill 2196 has been renamed West Top.

The 1:25000 map is misleading, as the summit is within the 440m contour ring 160m to the east of the easterly 442m spot. Furthermore, the largest scale on Geograph gives a 441m spot height at the summit, lower than the other two contenders and contradicting the survey results.

Fan Brycheiniog (2230/5603, 32A)
The 1:25000 map shows two 802m heights 300m apart. The Nuttalls' book regards them as twin summits, while Terry Marsh claims the trig point is higher. The editorial team surveyed the hill on 13 September 2011 on an occasion to mark the 10th anniversary of the Database of British Hills. The northern summit, Twr y Fan Foel (hill 5603) is 0.75m higher than the trig point (hill 2230). The result has been accepted by the list authors, so the Marilyn, Hewitt and Nuttall move to hill 5603. Hill 2230 remains the Buxton & Lewis, Bridge and Trail 100 top.
Mynydd y Grug (5273, 32C)
Old maps show the summit within a small 1175ft contour (358m) close to a trig station. The natural summit is now completely covered by a large spoil heap which is in the process of being drained and landscaped. The summit of the tip lies within a 370m contour, and a 375m spot height is shown on the OS Openspace vector map. Version 12 of the database gave the latter height, but as pointed out by David Purchase, this is inconsistent with the hill's classification because it would make the summit higher than 2297 Mynydd Machen (362m), implying a reversal of the col positions and relocation of the Marilyn. Alan Dawson considered the evidence and decided that the landscaping was insufficiently complete for the spoil heap to count as a hill. Accordingly, he reported on the rhb group that the Marilyn would remain Mynydd Machen for the time being. The majority of comments on the rhb group supported this decision. Photographs of the summit area can be viewed on Summits and Portraits of the Database of British and Irish Hills (click on the image to view other photos) and on Geograph.

Summits and Cols decrees that for an unfinished or incompletely landscaped artificial hill, a point on the perimeter is chosen to represent the summit. Given the vegetation on the slopes, the highest natural ground would probably be difficult if not impossible to ascertain on the ground. The choice of location is of some importance because if the height were below 353m the hill would cease to qualify as a Hump. After comparing the modern 1:25k map with the 1951 1:25k map, we have chosen a point at ST 1755 9075 at which the old path from the west has been diverted northwards to join the bridleway. It lies just below the 360m contour on the modern map. However the spoil heap is steep-sided and a height of c.355m is more consistent with the old map. The path is probably lower than than the trig point which is shown as 1171ft (357m) on the 1961 1" map. The contours on the modern 1:25k map are accurate to about ±5m whereas the trig height is accurate to ±2ft.

Garth Hill (7675, 32C)
Old large scale maps give a trig height of 848.5ft for the summit, and a levelled height of 514ft near the col. Smaller scale imperial maps are consistent in giving 849ft, which became 259m on early 1:50000 maps. Metric maps give an air height of 257m for the summit, and a height of 157m further from the col. Because levelled heights are much more accurate than air heights, and the 514ft spot is closer to the col, we regard the old maps as giving the best estimate of drop. An estimated col height of 515-516ft would give a drop of 101-102m. We have taken a conservative view by retaining the col height at 158m and increasing the summit height to 259m. The local correction to the Newlyn vertical height datum is -0.3ft.
Housedon Hill (2318, 33)
RHB gives the north top, which has a 267m spot height on the 1:50000 map misplaced on a 260m contour. This probably originates from a 876.9ft surveyed height on the 1866 1:10560 map which the old map marks on the boundary. The south top has a 266m air height on the 1:25000 map. Ground observations by George Gradwell with an Abney level found that the northern top lies near the edge of the wood and is marked by a small cairn. He also determined the south top to be marginally higher than the north top. A more detailed Abney Level survey found the south top to be 1m higher.
Armboth Fell (2483/3761, 34B)
Wainwright and Birkett give different locations for their respective summits on Armboth Fell. The Birkett summit is a large rock outcrop with a small cairn at the 479m spot height (NY 29677 15967). The Wainwright summit is a rock and heather outcrop at NY 29584 15740. Photograph 1 shows this summit alongside Wainwright's sketch. The cairn has been reduced to a mere handful of stones and is no longer visible from below. Supporting evidence for the location of Wainwright's summit is provided by photograph 2 which shows the "shepherd's cairn on a rock" alongside Wainwright's sketch. This can be found on a rocky outcrop at NY 29631 15534, which is almost exactly a furlong south of the Wainwright summit cairn. Again, the cairn on this boulder has been removed or destroyed. The prominence east of north mentioned in Wainwright's summit description is probably the 479m spot height.
Wether Hill (2557/2927, 34C)
Formerly the Nuttalls listed the north top (hill 2557), which is the Wainwright and Birkett summit. Several visitors to Wether Hill have noted that the south top (hill 2927 and the Buxton & Lewis summit) appears to be the higher and this is supported by modern and old maps. The current 1:50k OS map shows a large 670m ring contour on the south top and a 670m spot height with no ring contour on the north top. The 1:25k map has a large ring contour on the south top and a small 670m ring contour on the north top. The 1863, 1899 and 1919 1:10560 maps have a 2203.0ft (671.4m) benchmark at the boundary stone on the north top (although this is not quite at the summit), while the 1899, 1919 and 1956 1:10560 maps have a 2211ft (674m) spot height on the south top, about 70m south of the summit. Both heights also appear on the 1915 1:2500 map, as does a 2186ft spot height (666m) which is a plausible candidate for the col. These old levelled heights are shown superimposed on the 1:25k map; the arrow shows the position of the 10-figure grid reference formerly in the database (it was replaced in v12.1 by NY45461630 20m SSW following the Abney survey). A detailed survey by Jim Bloomer with an Abney Level estimated the south top as 3-4m higher than the north top, supporting the mapping. The Nuttalls announced the move on 7 March 2012.
Baystones [Wansfell] (2607/3838, 34C)
This hill has see-sawed in status. The original RHB publication (1992) lists Baystones as a Marilyn at NY403052 on the north side of the wall (hill 3838). All OS maps show a spot height of 487m at this point. It was demoted in 1995 when the drop was revised to 149m. Baystones was reinstated in May 2001 with relocation to NY403051 on the south side of the wall (hill 2607) following information from the OS that suggested its height might be 488m. We have surveyed the hill by differential GPS and find the summit height to be 486.9m and the drop 147.7m. The second demotion of Baystones was announced on 11 Feb 2010. The northern summit was estimated as 0.83m lower by optical levelling and therefore 486.1m in height.

Prior to v11 we did not list the two summits separately. Hill 3838 was added to distinguish the location of the Birkett from the Wainwright and (sub)Marilyn.

Wallow Crag [nameless - Naddle Horseshoe 2] (3329, 34C)
The location indicated on Wainwright's sketchmap does not match the route description, which in fact follows the ridge to Wallow Crag. There is no doubt of the correct summit as the sketch of the cairn on p.227 of The Outlying Fells of Lakeland matches the photograph on p.202 of Birkett's The Complete Lakeland Fells (the original photo is in colour but the scan has been reproduced in b/w to match Wainwright's sketch). The 410m contour ring at NY497148 is at best 412 metres high and is nothing more than a heathery mound that has clearly never had a cairn on it. Birkett's location is verified in a photograph of Wallow Crag taken by George Gradwell.
Great Yarlside (3661/2575, 34C)
Added to the Deweys in 2005 on the basis of measurements on a walker's GPS instrument, but deleted on 16 November 2011 after a levelling survey demonstrated that the hill lacks the required 30m of ascent. The Wainwright Outlying Fell is hill 2575, close to a 19th century circular trig station. The height was mistakenly given on OS maps as 1986ft (605m) at one time, probably a transcription error as it was previously 1936ft, leading Wainwright to choose that location.
Arnside Knott (3321, 34D)
New Marilyn reported in 2005 in Marhofn, previously not even a Submarilyn. A survey in October 2010 found the drop to be 150.8 ± 0.4m. The critical measurement is the height of the col, which is in a railway cutting. The survey of the col is recorded in a video.
nameless (Top o'Selside - Brock Barrow) (3335, 34D)
Wainwright mistakenly applies the label 748' a nameless summit (p.92 of The Outlying Fells of Lakeland) to the square cairn at SD 29814 89815, height 221m (725ft). A survey by Jim Bloomer and George Gradwell with an Abney level established that the true summit, a 229m spot height on OS maps, is a rock outcrop at SD 29885 89889. The square cairn was probably the highest point on Wainwright's route over the fell to a second cairn at SD 29809 90026 (sketch on p.94). We estimate the second cairn (within a small 700ft contour on the 1:10560 map) to be at least 5m lower than the square cairn and yet Wainwright declares it to be at approximately 730ft, supporting our conclusion that he believed the square cairn to be at the 748ft spot. The positions of the two cairns and the true summit are shown on this map and photograph.
Burnhope Seat (2714, 35A)
The Nuttalls give the trig point at NY788375 (746m), 350m from the true summit. They reported visiting the cairned point but did not think it was higher. Two independent surveys by Abney level confirm our location, approximately 100m west of the 747m spot height on the OS 1:50000 map.

The trig point is the historic County Top of Durham. In v14 we created a new hill (8036) for this summit, which is also the Bridge and Buxton & Lewis top. It is a moot point as to whether the Nuttall should be taken as the location given in the book or, given the prominence definition, the surveyed location. To avoid compromising the logs of walkers who only visited the trig but regard the Nuttall as bagged, we have retained the Nuttall as hill 2714 and amended the entry in the Comments field.

The only other Nuttall with a non-trivial difference between the surveyed and book locations is 2028 Pen y Castell, where the separation is 230m.

Thack Moor (2770, 35A)
The summit is 15m east of a trig point whose height is given on maps as 609m. A survey in August 2012, in which 2 hours of data was collected by our Leica 530 differential GPS system, obtained a result of 609.64m. On the Ordnance Survey's recommendation, a further survey was conducted in March 2013 in which 4 hours of data was collected using our recently acquired Leica GS15 system. This dataset gave a height of 609.62m. The data were sent to Ordnance Survey who processed them through their own software and obtained 609.62m from both datasets. Hence Thack Moor exceeds 2000ft by 2cm, or less than an inch. OS accepted the result and show 610m on current maps. The Nuttalls, Alan Dawson and Michael Dewey also accepted the result, thereby promoting the hill to Hewitt and Nuttall and deleting it from the Deweys. The news was announced by Grough on 3 April 2013. For further details see the survey report. Following the refinement of Ordnance Survey's geoid model on 26 August 2016, the height has been revised to 609.65m.

This is the converse of the original result for Calf Top, another hill with a summit close to a 609m trig point where 6 hours of data collected on two surveys gave a height of 609.58m, 2cm below 2000ft, before the adoption of the new geoid model took it above the threshold.

Hand Lake (3608, 35A) and Linghaw (3609, 35A)
Added to Michael Dewey's published list after discovery of tiny 500m contours on the 1:25000 map. Linghaw was subsequently demoted on 22 October 2010 after a survey revealed the height to be 498.8m, and Hand Lake on 25 November 2010 after the height had been measured as 499.6m. Contours on OS maps at 10m spacing are stated by the OS to be accurate to ±5m. Marginal Deweys have been a target of our surveying team since 2007, which has resulted in several changes to the list. For a complete list of changes see the Dewey change register.
Calf Top (2797, 35B)
Calf Top, a Dewey in the Yorkshire Dales, has been surveyed a total of three times by G&J Surveys. The estimated height was 609.58 ± 0.1m. As this was below 609.6m, the probability that the hill exceeded 2000ft was less than 50%, albeit marginally. Alan Dawson, John Nuttall and Michael Dewey were consulted and all were content for the hill's status to remain unchanged. For a summary of the surveys and the rationale for preserving the status quo, see Is Calf Top a new 2000ft mountain?. Then on 26 August 2016 Ordnance Survey refined their geoid model, which gave a new OS ratified height of 609.606m. The list authors were again consulted and agreed to promote the hill to Nuttall and Hewitt and delete it from the Deweys.
Birks Fell (2799, 35B)
Early lists of the English 2000s included Birks Fell on the basis of the 610m spot height at SD918763 on 1:50000 Landranger and earlier imperial maps. Later metric maps at 1:10000 and 1:25000 scale gave a 608m spot height at SD916764 instead. This caused the hill to be dropped from subsequent lists, and for the Marilyn to be moved to Horse Head Moor. The situation was confused by the continued appearance of the 610m spot on 1:50000 maps (known to be a metric conversion of an older imperial height) and a stream of visitors opining that the new 608m spot was not at the highest point. The OS was contacted but merely confirmed 608m as the highest recorded point on the metric contour document.

The impasse was resolved when our survey team surveyed the hill using a precision optical level. A follow-up survey confirmed their finding that the hill was definitely above 2000 feet, their estimate being 610.4 ± 0.2m or between 2002 and 2003ft. Details of both surveys can be read in Survey Reports. Subsequently the Nuttalls obtained a revised figure of 2001ft at SD919764 from the OS (from a 1920 levelling survey) which they indicated will appear on the next update of the 1:25000 Explorer. The OS later (19 Dec 2007) indicated that the new 610m spot will be shown at SD 9186 7637, a little to the south west of the cairn and in agreement with the 1:50000 map. However they appear to have erred in putting the 610m spot at SD916763 on the latest 1:25000 map, approximately the same position as the previous 608m spot.

Raw Head (2828, 36)
Demoted to SubMarilyn after extensive surveying showed it to have a drop of 148.5m. Alan Dawson accepted the change on 16 April 2009, some weeks after the survey results, in an announcement on the rhb group. Independent data from digital elevation models dismiss any real possibility that the col for Raw Head might lie in an area outside the surveyed region.
Viking Way (5466, 37)
The historic county top of Lincolnshire (Parts of Kesteven) lies on an ancient road probably dating from the Bronze Age, which follows the county boundary with Leicestershire hereabouts. In the 18th century it became used as a drove road, when it became known as Sewestern Drift or The Drift, the latter name being shown on maps. The ancient road forms part of the Viking Way, a modern long distance footpath.

The man-made road has been raised above the level of the surrounding land, at least in parts. The contouring on the modern map suggests two possible locations for the natural summit (i.e. before the building of the road), each within a 150m contour. The southern location is at SK889236 and the northern at SK851310. A site visit confirmed the impression from photographs that at the southern location, 40m south of the crossroads, the road lies on a shallow embankment c.40m wide at the base and perhaps 2m high. The 10-figure grid reference in the database is for the locally highest point, determined by Abney Level as c.0.5m higher than the crossroads. The 1976 1:2500 map has a ground height of 150.8m at the crossroads (151m on the 1983 1:10000 map and on Geograph mapping); the 1888 1:2500 map has a 495ft spot height at the crossroads and a picket benchmark at 495.2ft at the south corner of the wood.

Large scale maps show that further south the embankment rises. The 1976 1:2500 map gives two 152.3m spot heights at SK 8892 2333 and SK 8889 2309. The latter location has a 152m spot on the 1983 1:10000 map and on Geograph mapping and is coincident with the locally highest ground determined by Abney Level. However the ground falls away more steeply on both sides of the road than to the north, perhaps 4m vertically to the east and 3m to the west. The original ground beneath the embankment is therefore probably lower than at the location 40m south of the crossroads, as suggested by the contouring. Our Summits and Cols protocol decrees that a man-made feature can only be adopted as the summit when it overlies the natural summit. We have therefore discounted the 152.3m location as a candidate for the summit of the County Top.

We have not visited the northern summit, for which there are no spot heights on old or current maps. However the natural summit could well be at this location, particularly if the contour at the southern summit includes the embankment. Hence we recommend that both summits are visited.

Milk Hill (2872, 39)
Briefly acquired Marilyn status in 1997 when the TACit Table The Hewitts and Marilyns of England erroneously listed it in Section 42. A survey on 20 April 2009 confirmed the hill's status as both Submarilyn and the highest point of Wiltshire, being 0.25m higher than nearby Tan Hill. The OS confirmed these findings in their own survey. The survey was sponsored by the BBC and presented in a Countryfile programme on 23 August.
Botley Hill (2910/3686, 42)
Several walkers queried the original location, suggesting that there was higher ground within the large 265m contour to the west of the trig point. The 1:63360 OS map gives a spot height of 882ft and on the strength of this evidence Alan Dawson announced a relocation in June 2008. A line survey confirmed that the highest natural ground is at TQ 38708 55182 around the base of the water tower compound, ca. 3 metres higher than the trig point flush bracket.

The relocation of this hill raises a bagging ethics issue for those who have only visited the original location. A resident of Scotland might feel aggrieved at having to make the long journey south to reclaim the Marilyn. However the Marhofn editor instructed HoF members to reduce their year-end total by 1 if they had not done so. A similar issue arose with the replacement of Sgurr a'Bhac Chaolais by Buidhe Bheinn, although many would regard it as de rigueur to climb both summits of a twin Marilyn.

Crocknasmug (20445, 45A) and Crockaulin (20886, 45A)
The original TACit publication (1997) listed Crocknasmug as the 328m Marilyn. Clements' note 189 states "328m given here is from OS4 (OSNI); only a 322m spot height on OS3 (Republic) at C656438. Were this point the summit, then Crockaulin, 325m, at C624420 would become the Marilyn". The 2009 digital OSNI mapping now duplicates the OSi 322 spot. This replacement of the old 328m height with a nearby 322m spot height, combined with a visit to both sites, led to the conclusion that Crockaulin (3.8km SW) was probably higher. In 2012 a survey with a Trimble GeoXH6000 gave Crocknasmug 328m and Crockaulin (ground 200m N of trig) 326m. Consequently we have reinstated Crocknasmug as the Marilyn.
Bunnanimma (20656, 56A)
This hill has been relocated twice and undergone a name change. To simplify the narrative below, the locations are referred to as follows:
  • Point A: original location, H736153, Carrickatee
  • Point B: first relocation, H726148, Carrickatee (Carrickaveilty on maps)
  • Point C: second relocation, H718146, Bunnanimma
In The Hewitts and Marilyns of Ireland published by TACit Press, Clem Clements listed point A as a 270m Submarilyn with c.148m drop. When the hill entered the DoBIH in 2011 it was relocated to the 270m trig at point B and the col height increased by 10m, causing it to be deleted from the Submarilyns. Then in 2014 David Purchase wrote to us to propose a relocation to point C based on a site visit in 2003. He commented that although the original OSi maps D28A and D28B spotted point C at 266m, as does the OSi viewer, the current D28 map (an OSNI production) shows a small 270m contour there without a spot height. He found no trace of a trig pillar at point B. A poster on MountainViews confirmed the lack of a trig pillar and was informed by OSi that the trig is not a pillar but the top of a water tower. The original (1982) D28 map shows a 266m spot height a short distance SE of where the trig symbol is now shown, which in Purchase's opinion is close to the natural summit of point B. The same map gives a tiny 270m contour at point C partially obscured by the name Bananimma (which does not appear on the current D28 map), and a 270m spot at point A, the source of the TACit data. However Purchase was convinced from ground observations that the latter height is incorrect. The current D28 map shows just a 260m contour at point A. The 19th century 1:10560 map gives an 884ft trig at point A, which converts to 266.7m when adjusted to the Malin Head datum. This map also gives a 886ft trig (267.4m) at point C labelled Bunnanimma, whereas the 1:2500 map, which has a more modern appearance, gives 888ft (268.0m) and the name Bananimma. Neither imperial map gives a height for point B.

We have agreed with MountainViews a relocation to point C, with adoption of the name Bunnanimma and 268m for the summit height.

Alderney Airport, NE perimeter (7816, 57)
The 1966 1:10560 map (still available) gives two 294ft spot heights near the eastern and western edges of a wide 290ft contour. The eastern spot, named "Le Ronde But" (Le Ronde Butt on the States of Guernsey Official Map) also appears on the Admiralty chart. The other 294ft spot is 350m west near Le Callier. There is a much smaller 290ft contour NE of the airport runways that corresponds to the small 90m contour on the States of Guernsey Official Map. This is the location we give in the database. The States of Guernsey Official Map gives no other 90m contour, and only an 85m contour encircling the other locations. Note that the 1:12500 International Travel Map uses the old UTM30 grid, as does the 1:10560 map.

The States of Guernsey Official Map (2010) has no spot heights.

Les Platons, Jersey (7817, 57)
Our data are taken from the 1969 Directorate of Military Survey map, which shows a 446ft spot at Les Platons labelled "Highest Point". This location is also claimed to be the highest in Jersey in current tourist literature, including a cycling map. The Ordnance Survey published an Official Leisure map in 1981 based mainly on earlier surveys (not by the OS) supplemented by aerial photography flown by the OS in April 1980. The 1981 map has no "highest point" but spot heights make it clear that the location described is >435ft. The current 1:25000 Official Leisure Map of Jersey (revised 2011) gives a height of 134m on La Rue des Platons to the south.

Both imperial maps show a 460ft contour ring NE of Les Platons centred at WV658560 on the old UTM grid system. The current map has a 140m contour here, centred on WV657557 on the new UTM30 grid. The 1969 map gives a spot height of 376ft (115m) within this contour; the other maps have just the contour ring. However the 1969 map has colour-coded topographical shading and there is only one 400ft contour on Jersey. Within that contour, the next highest spot after Les Platons is 436.7ft at WV662553. It seems clear that that the 460ft/140m contour is actually 360ft/110m and a labelling error in the early map has been propagated in modern maps. This may be the source of the 143m "unnamed location" quoted in the CIA World Factbook and reproduced in other web pages, which some articles have subsequently associated with Les Platons.

The Access database

The Access 2000 database, which can be used with any later version of Access, has a fully relational structure. You do not need to own a copy of Microsoft Access in order to use the database, as you can install a free runtime version provided you have Windows XP Service Pack 2 or a later version of Windows. See downloads for instructions.

The Hills table is at the core of the database. Classification (hill list) and Area information are in separate tables, with "link" tables to identify the Classes and Areas to which a hill belongs.

You do not have to be knowledgeable about relational databases to use it. Viewing hill data, and logging your ascents, are simplified by the provision of a number of forms and screens.

The Userlog facility allows you to record date climbed and other details of the ascent. There is a User table that allows multiple users to share the same copy of the database, each maintaining separate logs. Users pursuing second or subsequent rounds will find it helpful to assign separate user names to each round in order to monitor their totals for the repeat rounds.

On opening the database you are presented with a Welcome screen, which is the start point for all the facilities provided by the database. It provides the following options.

  • Hills Database: This is the main screen for searching the database and logging personal ascents.
  • User Totals: Provides a summary of your progress against all the popular hill lists in Britain. You can view totals for two users at the same time, side by side.
  • User Progress: Provides a breakdown by year, or by month, of the number of hills you have climbed.
  • User Compare: List hills climbed by one user but not by another, or hills climbed by both, or hills climbed by neither.
  • User Logs: View your complete set of logs, in descending order of date climbed.
  • User Details: Change your User name, or add additional Users to the database.
  • Import Logs: Quickly import your logs from an earlier version of the database, or using a CSV extract of your logs from Hill Bagging.
  • Export Logs: Create a CSV file of your logs, which can be opened in a spreadsheet such as Excel or imported to Hill Bagging.
If you have closed the Welcome screen, it can be accessed from the Forms menu.

Uploading grid references to a GPS

Later GPS devices connect to a computer via a USB cable and are displayed as a drive in the computer's directory tree. These models include Garmin eTrex 10, 20, 30 and the Oregon and Montana series.

Older devices, e.g. the earlier eTrex models, connect to a computer via a com port. A USB conversion cable can be purchased, but some users have reported difficulty in getting it to function.

Grid references are uploaded to the two types of instrument in different ways.

Uploading grid references to later models

Ten-figure grid references of all hills are available in a Point of Interest (POI) file accessed on the downloads page or from a query in the Access database. Bernie Hughes' file contains all British hills in the database. The facility on Hill Bagging allows the user to select a subset of hills meeting particular criteria. The latter has a "long" version that includes all the key fields in the database (as does Bernie Hughes' file), and a "short" version that has only the location, hill name and height. The "POI csv extract" query in the Access database (accessible from the Queries menu in the DoBIH_v15:Database screen) returns the "long" version.

Connect your GPS to your PC. Create a subfolder named POI in the Garmin folder of the GPS and copy the file into it. No further action is needed for Bernie Hughes' file as it is already in gpi format. If you created the file in Hill Bagging or Access, save it as filename.csv (rather than .txt) and upload it to your Garmin device using Garmin POI Loader. NB. Do not use numeric characters in your filename – they will cause speed/proximity alerts to be added to your POI.

Disconnect the GPS from the PC and switch it on. You might have to experiment to learn how to display all the data in the POI file. On a Garmin eTrex 20 the process is as follows (Click means push down on toggle switch):

  1. Where to? Click.
  2. Extras. Click.
  3. Choose relevant database e.g. Hills. Highlight and Click.
  4. Highlight required hill. Click.

You will now have a screen with the name of the hill at the top, map in centre and Go button at bottom.

  1. Push toggle upwards and Go will disappear.
  2. Click and hill data should now appear with Go button reinstated on screen.

For the models listed above the screen will display all the hill details in the POI file, viz. name, height, ten-figure grid reference, hill number, classification, feature, and (depending on the file) other fields such as climbed date, drop, map, observations, survey and comment fields. The fields following the name, height and ten-figure grid reference are combined and presented in the Comment box of the instrument. Note that some earlier models with USB connectivity (not in the list above) do not have a Comment box and therefore do not display this information. The "short" version obtained from Hill Bagging is suitable for those. We would be grateful for information on other models.

For hills where no ten-figure grid reference has been recorded, the grid reference is for the SW corner of the 100m square in which the summit is thought to reside and consequently the GPS will not take you to the summit itself. These hills are easily identified in instruments where a Comment box is displayed because such hills lack a feature, observation and survey entry.

Waypoints may be uploaded to the GPS via a GPS exchange (gpx) file. This can be created using the facility on Hill Bagging mentioned above (link on Downloads page). Alternatively, it can be created in GPS Utility by a similar method to that described below, i.e. by creating a text file from a csv file using GPSU File Converter, opening it in GPS Utility and then saving it as a gpx file. The file may then be copied to the GPX subfolder in the Garmin directory of the GPS.

Uploading grid references to early models

Grid references from the database can be uploaded to a GPS unit using appropriate software. We are aware of three websites that offer such software: GPS Utility, G7toWin, and Oziexplorer. GPS Utility and Oziexplorer are commercial packages but evaluation copies can be downloaded free of charge. G7toWin is freeware. We have evaluated GPS Utility and G7toWin. We understand that Anquet Maps and Memory Map also have facilities for importing grid references but we have not investigated these.
Instructions for GPS Utility
Download both GPS Utility and GPSU File Converter. The latter converts files with a csv extension to text files that open in GPS Utility. The steps involved in the process of uploading a file to a GPS are as follows.
  1. Create the appropriate csv file for the data you wish to upload. We have provided a small csv test file with some British hill data for test and set-up purposes
  2. Open the csv file in GPSU File Converter and save this as a text file
  3. Open the text file in GPS Utility and transfer the data to the GPS.
The following describes the process in more detail for a Garmin eTrex. We have also successfully uploaded files to a Garmin eTrex Venture and a Garmin GPSMAP 60c. Both GPS Utility and GPSU File Converter have excellent and extensive Help files.
Setting up GPSU File Converter
Open the application and enter the following information:
  1. In 'Convert to' select Waypoints
  2. In 'Waypoint Settings' select Garmin(2-byte) for 'Symbol Set Type' and choose Comment in 'Text Option'
  3. Under 'Grid' and 'Datum' select the following:
    — for Great Britain, British Grid and Ord Srvy Grt Britn
    — for Ireland, Irish Grid and Ireland 1965
    — for Channel Islands, UTM and WGS84
  4. Note that you can choose to ignore the first line of a data set. This is useful when a file contains headers, e.g. our test file
  5. Right-click on the first column header and from the drop-down list select ID
  6. Right-click on the second column header and from the drop-down list select 'other' and then 'Grid' from the two available options. This tells the software to expect the grid reference in one field rather than split into eastings and northings
  7. Right-click on the third column header and from the drop-down list select 'Altitude' and then 'metres' from the three available options
  8. Right-click on the fourth column header and from the drop-down list select 'Comment'.
GPSU File Converter should now be able to open the test file. ID is the unique hill number, Grid (Zn E,N) is the ten figure grid reference, Alt(meters) is the height of the hill in metres and Comment is the hill name. Once open, click 'Export aS' and save as a text file.
Setting up GPS Utility
  1. Open GPS Utility
  2. Under 'GPS' in the main menu select 'Set-up' from the drop-down list
  3. In the Interface Setup dialogue box that opens:
    — for 'GPS make/Interface mode' select Garmin(Serial;USB/Serial)
    — for 'Type/Family' select eTrex
    — for 'Model' select generic
    — for 'Com Port Number' confirm that the com port to which your GPS is connected is selected
  4. Under 'Options' in the main menu, select 'Grids' and ensure British grid and/or Irish grid are available
  5. Under 'View' in the main menu, select 'Datum' and choose Ord Srvy Grt Britn, Ireland 1965 or WGS84 for Great Britain, Ireland and Channel Islands respectively
  6. Still under 'View' in the main menu, select 'Coordinate System' and choose British Grid, Irish Grid or UTM/USP for Great Britain, Ireland and Channel Islands respectively
GPS Utility should now open the text version of our test file that you have just created in GPSU File Converter. If you wish to upload all of the grid references to your GPS select 'upload all', otherwise select those you wish to upload and then select 'upload Highlighted all'. The grid references will then be uploaded to your GPS.

Note that it is the unique Hill Number that is transferred to the GPS in our test file and not the Hill Name. The earlier eTrex models only accept six characters for a waypoint name and most hill names are much longer than this. Unique Hill Numbers do not exceed six characters in length. When starting a walk, the appropriate Hill Number will be visible in MapView (when set to the appropriate scale) on the eTrex and the user will be able to identify the correct hill to select in GOTO when approaching the summit area. We have uploaded a dataset of twenty hills to a Garmin eTrex and successfully navigated to all of them in this way. Whilst the hill name is a useful identifier in the csv file, it is not necessary once the whole dataset is in the GPS. However if the user prefers to abbreviate hill names and use these as the ID, this is easily accommodated by GPS Utility.

GPS Utility (GPSU) text files can also be created in Hill Bagging.

The ten-figure grid references in the database will usually take the user to within 5m of the target feature. The database is available in csv format from the downloads page, while user-specified subsets can be created by the Hill Bagging website to registered users. We recommend you use one of these versions to create the files for uploading to your GPS.

We are grateful to Darren Parker who first kindled our interest in uploading ten-figure grid references from the database to a GPS instrument, and to Bernie Hughes for first creating POI files from the database.

Recreating the original lists

Microsoft Access users can easily extract individual lists, including subsets, using the search facility. Users of the Excel or text versions of the database can recreate many of the original lists, approximately, by sorting on the relevant category field followed by Area (for Donalds, Nuttalls and Wainwrights) or Section (for The Relative Hills of Britain and TACit Tables – note the earlier publications do not subdivide sections 5, 6, 8 and 26). In Excel, the easiest way of selecting hills belonging to a particular category is to use the Autofilter facility in the Data menu. This is already set up in the file.

For Marilyns and Grahams, the hill order in RHB/TACit can be reproduced approximately by further sorting by descending height.

User feedback and database enhancements

We welcome users' suggestions for enhancing the database, and of course reports of errors.

We are particularly keen to receive 10 figure GPS measurements from readers. Please see under 10 Figure Grid References for the information we need.

The DoBIH fund

The fund was set up in response to offers from a number of users to contribute to the costs of maintaining the database. It is managed by John Barnard and Graham Jackson and is currently used to support our surveying activity. The cost of equipment and maintenance is considerable and was originally borne entirely by the editors.

Hill surveying was pioneered by the DoBIH as a means of gaining accurate data on hills where height, drop or location are critical. Surveys carried out by the survey team (G&J Surveys) are carried out to professional standards and, subject to validation, data is accepted by Ordnance Survey as it is collected to OS protocols. Hills where OS has adopted new summit heights supplied by the team include Sgurr nan Ceannaichean, Beinn a'Chlaidheimh, Beinn Dearg Mor, Knight's Peak, Carn na Caim South Top, Creag na Caillich, Glyder Fawr, Tryfan, Mynydd Graig Goch, Calf Top and Thack Moor.

The team has access to a Leica GS15 survey-grade GPS capable of measuring height to 5cm, a Leica NA730 automatic x30 telescopic level, a Leica Runner automatic x20 telescopic level, a 1m surveyor's staff extendable to 5m, three tripods and a Leica Disto A8 for measuring distance and angles. This suite of equipment enables them to determine absolute height and drop, usually to 0.1m or better, in almost any terrain.

We have received several donations from supporters and are very grateful to everyone who has helped us.

Anyone wishing to support the fund can do so via the PayPal link or by contacting one of the editors. A "to do" list of candidate hills for surveying is available in Excel and can be forwarded on request. If you have suggestions for hills to survey please forward these to . We welcome your input.


We thank Alan Dawson for many survey measurements, contributions to data revision, and constructive suggestions; Rob Woodall for his files on the rhb group and particularly his work on the British 500m hills; Alan Holmes for his work on the SIBs; Myrddyn Phillips and Aled Williams for use of data taken from Y Pedwarau and The Fours in revising the Tumps; Myrddyn Phillips for survey measurements and his listings of Irish 500s (the Myrddyn Deweys), 400s (via the Carns) and lower Welsh hills on; David Purchase for his work on the Donald Deweys and Channel Islands hills and help with the Dewey change register; John Fitzgerald and the MountainViews team for Irish survey data; Dave Marshall for assisting the editors with maintenance of the GPS database, data reviews and projects; Andrew Tibbetts, Martin Hampar, Bernie Hughes, David White and Tony Hartry for providing or reviewing hill data; Toby Thurston for supplying the boundary coordinates of Landranger and Explorer maps; Geoff Crowder for contributing to the revision of the Wainwright Outlying Fells; John Kirk for reviewing the P20 lists; Gordon Adshead for checking the first version of the database; all those who responded to the user surveys in 2008 and 2010; and many other correspondents who reported errors and suggested improvements.

We are grateful to the following walkers for contributing 10-figure GPS readings to the database: Adrian Snowdon, Alan & Kathy Duval, Alasdair Alexander, Alex Barbour, Andrew Brown, Andrew Round, Andy Lindley, Andy Tomkins, Andrew West, Anthony Duffield, Anton Ciritis, Bengt Karlsson, Bernie Hughes, Bert Barnett, Bill Morden, Brian Diggle, Carolyn Hastings, Charlie Scrimgeour, Chris Bienkowski, Chris Clissold, Chris Derrick, Chris Peart, Chris Watson, Chris Walker, Clive Richardson, Colin MacKenzie, Conrad Izatt, Craig Mungin, Dale Wilson, Darren Groutage, Dave Marshall, David Baird, David Brown, David Butterfield, David Claymore, David Gradwell, David Purchase, David Williams, David White, Del Wilson, Dennis Foster, Derek Blackburn, Derek Norry, Derek Snaith, Des Taylor, Douglas Law, Gareth Solomon, Gerry Bowes, Grant Bain, Henry Marston, Ian Baines, Ian Henderson, Ken Wood, Iain Macaulay, Iain Rudkin, Idwal Jones, Jim Coombes, John Edwards, John Smith, John Stoneham, Jonathan Glew, Jonathan Russell, Judy Catterall, Justin Dunn, Ken Wood, Laurence Rudkin, Lindsay Boyd, Lindsay Shaw, Lionel Bidwell, Liz Nicholas, Lyndon Day, Malcolm Ratcliffe, Mark Smith, Mark Trengove, Martin Richardson, Martin Roberts, Michael Earnshaw, Michael Elcock, Mick Moore, Mike Mason, Mike Scott, Neil McVicar, Nigel Thackrah, Paul Cawley, Paul Heaton, Paul Kingston, Paul Miller, Paul Ward, Paul Woodcock, Pete Fairhurst, Pete & Barbara Nelson, Peter Cottam, Peter & Liz Hastie, Phil Catterall, Phil Sidwell, Richard Cooper, Richard Tibbetts, Richard Mclellan, Richard Webb, Rick Salter, Robert Davies, Robert Kerr, Robert Poole, Rob Woodall, Roger Hewitt, Ron Bell, Ronnie Bowron, Ross Drummond, Roy Davidson, Sandra Morrison, Simon Irons, Stephen Dawson, Stephen Walker, Steve Smith, Stuart Joynson, Stuart Lawson, Ted Richards, Toby Thurston, Tom Levell, Tony Hartry, Tony Jenkins, Tony Watson and Tuco Ramirez.

We are indebted to the authors of the lists given in this database, without whose efforts it would not exist: the SMC, Alan Dawson, John and Anne Nuttall, Michael Dewey, Paddy Dillon, Clem Clements, Simon Stewart, Chris Buxton and Gwyn Lewis, Bill Birkett, Timothy Synge, Mark Richards and Alfred Wainwright. Their publications are well worth obtaining as they make stimulating reading and contain much interesting background on the lists.

Updated 22 June 2017