Myrddyn Phillips - Mapping Mountains: Mapping Mountains – Significant Height Revisions

Thursday 26 October 2017

Mapping Mountains – Significant Height Revisions – The Fours - The 400m Hills of England

The Fours – The 400m Hills of England - Significant Height Revisions

The Fours - The 400m Hills of England are the English hills at and above 400m and below 500m in height that have 30m minimum drop. Accompanying the main list are three sub lists; these are the 400m Sub-Fours, 390m Sub-Fours and 390m Double Sub-Fours. With their criteria detailed in the Change Registers which are linked in the above titles.

The list is co-authored by Myrddyn Phillips and Aled Williams and the posts that have appeared on Mapping Mountains detailing the Significant Height Revisions to the main P30 list and the sub lists appear below presented chronologically in receding order.

Postscript: On the 10^th July 2024 the final group of hills in the updated version of this list were published on the Mapping Mountains site. It was also announced that the sub hills accompanying the main listing of The Fours – The 400m Hills of England now take in just one category, this category is entitled the Sub-Fours.

Therefore, the 390m Sub-Fours and 390m Double Sub-Fours have been dispensed with and the criteria for the 400m Sub-Fours that included English hills at and above 400m and below 500m in height that have 20m and more and below 30m of drop, have been amended to include English hills at and above 400m and below 500m in height that have 15m and more and below 30m of drop and their title changed to the Sub-Fours.

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Blackkip (NT 799 043) - 31st significant height revision

Hill Reclassifications post for Blackkip

Summit Relocations post for Blackkip

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Blackkip (NT 799 043)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Blackkip, and it is adjoined to the Thirl Moor group of hills, which are situated in Northumberland, and it is positioned with minor roads to its north, west and east, and the A68 road to its south, and has the small community of Rochester towards the south-east.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised. The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with an estimated c 14m of drop, based on the 445m summit spot height positioned at NT 79821 04293 that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 431m col height, based on interpolation of 10m contouring between 430m – 440m.

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed. The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image of Blackkip (NT 799 043)

LIDAR analysis gives the height of this hill as 448.6m positioned at NT 79958 04358, and when compared to its originally listed summit height of 445m this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR. Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 448.6m and this was derived from LIDAR analysis, this is 3.6m higher than its originally listed 445m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

The full details for the hill are:

Group: Thirl Moor

Name: Blackkip

OS 1:50,000 map: 80

Summit Height (New Height): 448.6m (LIDAR)

Summit Grid Reference: NT 79958 04358 (LIDAR)

Col Height: 429.3m (LIDAR)

Col Grid Reference: NT 80006 04487 (LIDAR)

Drop: 19.3m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2024)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

The Heart’s Toe (NT 766 069) - 30th significant height revision

LIDAR image of The Heart's Toe (NT 766 069)

The criteria for the list that this height revision applies to are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is The Heart’s Toe, and it is adjoined to the the Thirl Moor group of hills, which are situated in Northumberland, and it is positioned with the A68 road to its south and a minor road to its south-east, and has the village of Byrness towards the south.

Prior to this revision this hill was listed with 16m of drop, based on the 449m summit spot height and the 433m col spot height that appear on the Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR summit image of The Heart's Toe (NT 766 069)

LIDAR analysis gives the height of this hill as 450.1m positioned at NT 76665 06926, and when compared to its originally listed summit height of 449m this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 450.1m and this was derived from LIDAR analysis, this is 1.1m higher than its originally listed 449m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Thirl Moor

Name: The Heart’s Toe

OS 1:50,000 map: 80

Summit Height (New Height): 450.1m (LIDAR)

Summit Grid Reference: NT 76665 06926 (LIDAR)

Col Height: 434.1m (LIDAR)

Col Grid Reference: NT 76452 06833 & NT 76462 06833 (LIDAR)

Drop: 16.0m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2024)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Pt. 457.5m (NT 802 125) - 29th significant height revision

LIDAR image of Pt. 457.5m (NT 802 125)

The criteria for the list that this height revision applies to are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The hill is being listed by the point (Pt. 457.5m) notation, and it is adjoined to the The Cheviot group of hills, which are situated in Northumberland, and it is positioned with a minor road to its north-west and the A68 road to its south-west, and has the village of Edgerston towards the west.

Prior to this revision this hill was listed with an estimated c 19m of drop, based on the 460m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 441m col height, based on interpolation of 10m contouring between 440m – 450m.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR summit image of Pt. 457.5m (NT 802 125)

LIDAR analysis gives the highest natural ground on this hill as 457.5m positioned at NT 80259 12576, and when compared to its originally listed summit height of 460m this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 457.5m and this was derived from LIDAR analysis, this is 2.5m lower than its originally listed 460m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: The Cheviot

Name: Pt. 457.5m

OS 1:50,000 map: 80

Summit Height (New Height): 457.5m (LIDAR)

Summit Grid Reference: NT 80259 12576 (LIDAR)

Col Height: 439.0m (LIDAR)

Col Grid Reference: NT 80448 12940 (LIDAR)

Drop: 18.5m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2024)

On the 10^th July 2024 the Sub hills accompanying the main listing of the The Fours – The 400m Hills of England were amended. The 390m Sub-Fours and 390m Double Sub-Fours have been dispensed with, and the remaining 400m Subs are now entitled the Sub-Fours and their criteria amended to include all English hills at and above 400m and below 500m in height that have 15m and more and below 30m of drop.

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Three Barrows (SX 652 626) - 28th significant height revision

Significant Name Changes post for Three Barrows

LIDAR image of Three Barrows (SX 652 626)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, the 400m Sub-Four category, the 390m Sub-Four category and the 390m Double Sub-Four category. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Three Barrows, and it is adjoined to the Ryder’s Hill group of hills, which are situated in Dartmoor in the south-west of the country, and it is positioned with a series of minor roads to its south-west and south-east, and the B3213 road and the A38 road to its south, and has the town of Ivybridge towards the south.

Extract from the Ordnance Survey 1:50,000 Landranger map

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with a 464m summit height, based on the spot height that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and this is also the summit height used when the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018.

Extract from the Ordnance Survey 1:25,000 Explorer map

The highest measurement recorded from LIDAR analysis is 464.1m positioned at SX 65310 62600. However, LIDAR contouring and this position corresponds with that of an ancient cairn and as this is deemed not permanent in nature it is discounted from the summit height of this hill.

LIDAR summit image of Three Barrows (SX 652 626)

LIDAR analysis gives the highest natural ground on this hill as 461.3m positioned at SX 65286 62610, and when compared to its originally listed summit height of 464m this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 461.3m and this was derived from LIDAR analysis, this is 2.7m lower than its originally listed 464m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

The full details for the hill are:

Group: Ryder’s Hill

Name: Three Barrows

OS 1:50,000 map: 202

Summit Height (New Height): 461.3m (LIDAR)

Summit Grid Reference: SX 65286 62610 (LIDAR)

Col Height: 426.7m (LIDAR)

Col Grid Reference: SX 65153 63316 (LIDAR)

Drop: 34.6m (LIDAR)

Myrddyn Phillips and Aled Williams (March 2024)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Saddle Tor (SX 750 764) - 27th significant height revision

LIDAR image of Saddle Tor (SX 750 764)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Saddle Tor, and it is adjoined to the Broad Barrow group of hills, which are situated in Dartmoor in the south-west of the country, and it is positioned with minor roads to its north, north-west and north-east, and the B3387 road to its immediate south, and has the town of Bovey Tracey towards the east north-east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with a 428m summit height, based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the height of this hill was amended to 429.8m, based on analysis of available LIDAR.

LIDAR summit image of Saddle Tor (SX 750 764)

Analysis of the latest available LIDAR gives the highest ground on this hill as 430.0m positioned at SX 75066 76407, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 430.0m and this was derived from analysis of the latest available LIDAR, this is 2.0m higher than its originally listed 428m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Broad Barrow

Name: Saddle Tor

OS 1:50,000 map: 191

Summit Height (New Height): 430.0m (LIDAR)

Summit Grid Reference: SX 75066 76407 (LIDAR)

Col Height: 402.4m (LIDAR)

Col Grid Reference: SX 75260 76525 (LIDAR)

Drop: 27.7m (LIDAR)

Myrddyn Phillips and Aled Williams (March 2024)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Rippon Tor (SX 746 755) - 26th significant height revision

There has been a Significant Height Revision that is retrospective to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Rippon Tor (SX 746 755)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Rippon Tor, and it is adjoined to the Broad Barrow group of hills, which are situated in Dartmoor in the south-west of the country, and it is positioned with the B3387 road to its north and minor roads to its west and south-east, and has the town of Bovey Tracey towards the east north-east.

Extract from the Ordnance Survey 1:50,000 Landranger map

When the listing that is now known as The Fours – The 400m Hills of England was originally compiled by Myrddyn Phillips, this hill was listed with a 473m summit height, based on the spot height that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 1^st edition of the The Fours now co-authored by Myrddyn Phillips and Aled Williams was published by Europeaklist in December 2013 the summit height was amended to 477m, with an accompanying note stating:

Summit height from 1,563.8ft (476.65m [476.47m height relative to Ordnance Datum Newlyn]) levelled height on Ordnance Survey 1:2,500 map which matches the rounded up 1,564ft height on the Ordnance Survey New Popular One-Inch map. The imperial height of 1,563ft (476.4m [476.2m height relative to Ordnance Datum Newlyn]) is also recorded on the Ordnance Survey Seventh Series One-Inch map. Summit height of 473m on current Ordnance Survey 1:50,000 and 1:25,000 map. Triangulation pillar with 475.905m flush bracket height on summit area. The trig pillar is positioned within a wind shelter and is built on a concrete base with the ground at the base of the trig being approximately 475.555m - 475.605m in height, and as the high point of this hill is a substantial slab of rock positioned a few metres from the wind shelter and an approximate 1m higher than the base of the trig, the listed height of 477m can also be calculated from 475.6m (base of trig) + 1m = 476.6m. However, there's still an unusual 3.6m discrepancy in the current 473m Ordnance Survey map height.

When the 2^nd edition of The Fours – The 400m Hills of England co-authored by Myrddyn Phillips and Aled Williams was published by Mapping Mountains Publications in April 2018, the height of this hill was reassessed and it was listed as 476m, with an accompanying note stating:

476m summit height taken from the 1,563.8ft (476.65m) surface height on the OS Six-Inch map published in 1886. Triangulation pillar with 475.905m flush bracket height situated on the summit area and positioned in a wind shelter with its flush bracket 60cm lower than the summit of the hill, this corresponds with the 476.47m surface height relative to Ordnance Datum Newlyn. However, there is still an unusual 3.5m discrepancy between the 476.47m height and the current 473m OS map height.

LIDAR summit image of Rippon Tor (SX 746 755)

LIDAR analysis gives the highest ground on this hill as 476.3m positioned at SX 74661 75574, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 476.3m and this was derived from LIDAR analysis, this is 3.3m higher than its originally listed 473m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

The full details for the hill are:

Group: Broad Barrow

Name: Rippon Tor

OS 1:50,000 map: 191

Summit Height (New Height): 476.3m (LIDAR)

Summit Grid Reference: SX 74661 75574 (LIDAR)

Col Height: 357.6m (LIDAR)

Col Grid Reference: SX 73917 79116 (LIDAR)

Drop: 118.7m (LIDAR)

Myrddyn Phillips and Aled Williams (March 2024)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

South Hessary Tor (SX 597 723) - 25th significant height revision

Summit Relocations post for South Hessary Tor

Significant Name Changes post for South Hessary Tor

There has been a Significant Height Revision that is retrospective and due to a summit relocation to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of South Hessary Tor (SX 597 723)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is South Hessary Tor, and it is adjoined to the High Willhays group of hills, which are situated in Dartmoor in the south-west of the country, and it is positioned with the B3212 road to its north-west and a minor road to its east, and has the village of Princetown towards the north-west.

When the listing that is now known as The Fours – The 400m Hills of England was originally compiled this hill appeared under the name of South Hessary Tor North Top with a summit height of 451m positioned at SX 594 730, based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed as South Hessary Tor with a 454m summit height positioned at SX 597 723, based on the spot height that appears on the Harvey Maps 1:40,000 British Mountain Map to Dartmoor. This is also the summit height and position used when the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018.

Extract from the Harvey Maps 1:40,000 British Mountain Map to Dartmoor

LIDAR summit image of South Hessary Tor (SX 597 723)

LIDAR analysis gives the highest ground on this hill as 454.1m positioned at SX 59712 72361, as opposed to the originally listed summit position of 450.7m positioned at SX 59448 73056, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the listed summit height of this hill is 454.1m and this was derived from LIDAR analysis, this is 3.1m higher than the originally listed summit height which was based on the 451m spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: High Willhays

Name: South Hessary Tor

OS 1:50,000 map: 191

Summit Height (New Height): 454.1m (LIDAR)

Summit Grid Reference: SX 59712 72361 (LIDAR)

Col Height: 418.9m (LIDAR)

Col Grid Reference: SX 58746 73462 (LIDAR)

Drop: 35.2m (LIDAR)

Myrddyn Phillips and Aled Williams (February 2024)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Grindle (SO 430 926) - 24th significant height revision

Survey post for Grindle

LIDAR image of Grindle (SO 430 926)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Grindle, and it is adjoined to the Stiperstones group of hills, which are situated in the county of Shropshire close to the Welsh border, and it is positioned with minor roads to its north and west, and the B4577 and A49 roads to its east, and has the town of Church Stretton towards the east north-east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with an estimated c 53m of drop, with a 459m summit height positioned at SO 430 926 based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map and an estimated c 406m col height, based on interpolation of 5m contouring between 405m – 410m.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 460.2m summit height, based on a Trimble GeoXH 6000 survey.

However, it was not until LIDAR became available that the details produced by the Trimble GeoXH 6000 survey for this hill could be accurately re-assessed. The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image of Grindle (SO 430 926)

LIDAR analysis gives the highest ground on this hill as 460.5m positioned at SO 43009 92663, and this is being prioritised over the result produced by the Trimble GeoXH 6000, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 460.5m and this was derived from LIDAR analysis, this position is adjacent to where the 459m spot height appears on the Ordnance Survey 1:25,000 Explorer map and is 1.5m higher than it and importantly signifies contemporary Ordnance Surveys maps are missing an uppermost 460m ring contour.

The full details for the hill are:

Group: Stiperstones

Name: Grindle

OS 1:50,000 map: 137

Summit Height (New Height): 460.5m (LIDAR)

Summit Grid Reference: SO 43009 92663 (LIDAR)

Col Height: 406.6m (LIDAR)

Col Grid Reference: SO 42581 92764 (LIDAR)

Drop: 53.9m (LIDAR)

Myrddyn Phillips and Aled Williams (December 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Nipstone Rock (SO 356 969) - 23rd significant height revision

Survey post for Nipstone Rock

Nipstone Rock (SO 356 969)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Nipstone Rock, and it is adjoined to the Stiperstones group of hills, which are situated in the county of Shropshire close to the Welsh border, and it is positioned encircled by minor roads with the A488 road farther to its west, and has the small community of White Grit towards the west.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with an estimated c 22m of drop, with an estimated c 445m summit height positioned at SO 356 969 based on interpolation of the uppermost ring contour that appears on the contemporary Ordnance Survey 1:25,000 Explorer map and an estimated c 423m col height, based on interpolation of contouring between 420m – 425m.

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until the Trimble GeoXH 6000 survey that an accurate height for both the main summit of Nipstone Rock and its adjacent heather clad summit could be determined. This survey gives the highest ground on this hill as 447.0m positioned at SO 35668 96957 on the main Nipstone Rock summit , as opposed to 445.4m positioned at SO 35563 96815 to the adjacent heather clad summit, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The Trimble GeoXH 6000 gathering data at the summit of Nipstone Rock

The Trimble GeoXH 6000 gathering data at the adjacent heather clad summit

Therefore, the new listed summit height of this hill is 447.0m and this was derived from a Trimble GeoXH 6000 survey, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is 2.0m higher than the previously estimated c 445m summit height which was based on interpolation of the uppermost ring contour that appears on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Stiperstones

Name: Nipstone Rock

OS 1:50,000 map: 137

Summit Height (New Height): 447.0m (converted to OSGM15)

Summit Grid Reference: SO 35668 96957

Col Height: 423.9m (converted to OSGM15)

Col Grid Reference: SO 36160 97549

Drop: 23.0m

Myrddyn Phillips and Aled Williams (December 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Chrome Hill (SK 070 673) - 22nd significant height revision

LIDAR image of Chrome Hill (SK 070 673)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Chrome Hill, and it is adjoined to the Axe Edge group of hills, which are situated in the Peak District, and it is positioned with minor roads to its north-west, south and east, and the B5053 road farther to its east, and has the town of Buxton towards the north north-west.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 443m summit height, based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

Extract from the DataMapWales showing a 439m summit spot height

LIDAR summit image of Chrome Hill (SK 070 673)

LIDAR analysis gives the highest ground on this hill as 439.2m positioned at SK 07062 67341, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 439.2m and this was derived from LIDAR analysis, this position is close to where the spot height appeared and is 3.8m lower than the previously listed 443m summit height, which appeared as a spot height on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

The full details for the hill are:

Group: Axe Edge

Name: Chrome Hill

OS 1:50,000 map: 119

Summit Height (New Height): 439.2m (LIDAR)

Summit Grid Reference: SK 07062 67341 (LIDAR)

Col Height: 382.2m (LIDAR)

Col Grid Reference: SK 06904 67591 (LIDAR)

Drop: 57.0m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Soil Hill (SE 076 313) - 21st significant height revision

LIDAR image of Soil Hill (SE 076 313)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Soil Hill, and it is adjoined to the Pendle group of hills, which are situated in the southern Pennines, and it is positioned with the B6145 road to its north north-west, the A629 road to its west, a minor road to its south and the A644 road to its north-east, and has the town of Denholme towards the north.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 402m summit height, with an accompanying note stating; 402m summit height taken from the 1,320.4ft (402.46m) surface height on the OS Six-Inch map published in 1852.

Extract from the Ordnance Survey series of Six-Inch maps

However, due to quarrying activity the height of this hill was in flux. Therefore, it was not until LIDAR became available that the details for this hill could be accurately re-assessed. The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image of Soil Hill (SE 076 313)

LIDAR analysis gives the highest ground on this hill as 408.8m positioned at SE 07680 31368, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 408.8m and this was derived from LIDAR analysis, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is 6.8m higher than the previously listed 402m summit height, which appeared as a 1,320.4ft (402.46m) surface height on the Ordnance Survey Six-Inch map published in 1852.

The full details for the hill are:

Group: Pendle

Name: Soil Hill

OS 1:50,000 map: 104

Summit Height (New Height): 408.8m (LIDAR)

Summit Grid Reference: SE 07680 31368 (LIDAR)

Col Height: 348.6m (LIDAR)

Col Grid Reference: SE 06547 31672 (LIDAR)

Drop: 60.2m (LIDAR)

Myrddyn Phillips and Aled Williams (June 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Wadsworth Moor (SE 015 283) - 20th significant height revision

LIDAR image of Wadsworth Moor (SE 015 283)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Wadsworth Moor, and it is adjoined to the Pendle group of hills, which are situated in the southern Pennines, and it is positioned with a minor road to its south-west, the A6033 road farther to its west, and the A646 road farther to its south, and has the town of Hebden Bridge towards the south-west.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 409m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

A more accurate reflection of the summit height of this hill appears on the interactive DataMapWales

LIDAR summit image of Wadsworth Moor (SE 015 283)

LIDAR analysis gives the highest ground on this hill as 411.95m positioned at SE 01573 28371, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 411.95m and this was derived from LIDAR analysis, this position is relatively close to where the spot height appears, and is 2.95m higher than the previously listed 409m summit height, which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Pendle

Name: Wadsworth Moor

OS 1:50,000 map: 104

Summit Height (New Height): 411.95m (LIDAR)

Summit Grid Reference: SE 01573 28371 (LIDAR)

Col Height: 390.0m (LIDAR)

Col Grid Reference: SE 01164 29045 & SE 01166 29042 (LIDAR)

Drop: 22.0m (LIDAR)

Myrddyn Phillips and Aled Williams (June 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Jenny Binks Moss (SE 105 836) - 19th significant height revision

LIDAR image of Jenny Binks Moss (SE 105 836)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Jenny Binks Moss, and it is adjoined to the Whernside group of hills, which are situated in the central Pennines, and it is positioned with the A6108 road to its north-east, and a minor road to its north-west, and has the town of Middleham towards the north-east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 422m summit height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR summit image of Jenny Binks Moss (SE 105 836)

LIDAR analysis gives the highest ground on this hill as 419.7m positioned at SE 10504 83614, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 419.7m and this was derived from LIDAR analysis, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, although it is relatively close to where the 422m spot height appears, and is 2.3m lower than the previously listed 422m summit height, which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Whernside

Name: Jenny Binks Moss

OS 1:50,000 map: 99

Summit Height (New Height): 419.7m (LIDAR)

Summit Grid Reference: SE 10504 83614 (LIDAR)

Col Height: 390.6m (LIDAR)

Col Grid Reference: SE 10032 83010 (LIDAR)

Drop: 29.1m (LIDAR)

Myrddyn Phillips and Aled Williams (May 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Addlebrough (SD 947 878) - 18th significant height revision

Summit Relocation post for Addlebrough

LIDAR image of Addlebrough (SD 947 878)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Addlebrough, and it is adjoined to the Whernside group of hills, which are situated in the central Pennines, and it is positioned with the A684 road to its north, a minor road to its west and the B6160 road to its south-east, and has the village of Bainbridge towards the north-west.

When the original list that later became known as The Fours – The 400m Hills of England was first compiled, the summit position of this hill was given as SD 945 881 based on where the contemporary Ordnance Survey 1:25,000 Explorer map indicated an uppermost 480m ring contour to be situated.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with an estimated c 481m summit height, based on interpolation of what was indicated as its highest 480m contour ring that appears on the Ordnance Survey 1:25,000 Explorer map, with its listed summit position being relocated to SD 947 878.

LIDAR summit image of Addlebrough (SD 947 878)

LIDAR analysis gives the highest ground on this hill as 478.9m positioned at SD 94744 87872, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 478.9m and this was derived from LIDAR analysis, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is 2.1m lower than the previously estimated c 481m summit height, which was based on interpolation of what was indicated as its highest 480m contour ring, which LIDAR indicates is 470m in height.

The full details for the hill are:

Group: Whernside

Name: Addlebrough

OS 1:50,000 map: 98

Summit Height (New Height): 478.9m (LIDAR)

Summit Grid Reference: SD 94744 87872 (LIDAR)

Col Height: 386.8m (LIDAR)

Col Grid Reference: SD 94822 87149 (LIDAR)

Drop: 92.1m (LIDAR)

Myrddyn Phillips and Aled Williams (May 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Eastgate Quarry (NY 941 369) - 17th significant height revision

Hill Reclassifications post for Eastgate Quarry

LIDAR image of Eastgate Quarry (NY 941 369)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddn Phillips and Aled Williams

The name the hill is listed by is Eastgate Quarry and it is adjoined to the Burnhope Seat group of hills (Region 35, Section 35A: The Northern Pennines), and it is positioned with the A689 road to its north, and has the town of Stanhope towards the east north-east.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was not included in the accompanying sub list, as it was considered not to meet the criteria used for this sub category, based on the hill being a part of a quarry and therefore contemporary Ordnance Survey maps do not show any meaningful contours, with a 387m spot height appearing on the Ordnance Survey 1:50,000 Landranger map for the uppermost height leading in to this quarry.

Extract from the Ordnance Survey 1:50,000 Landranger map

Since the original publication of this list there have been a number of maps made available online. Some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website. Whilst others were digitally updated such as the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the WalkLakes and DataMapWales websites.

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme. This map has many spot heights not on other publicly available maps and although no spot heights are given for this hill, its contours show the hill exists.

Extract from the interactive mapping on the WalkLakes website

Another resource now available online is the interactive mapping hosted on the Welsh Government website and entitled the DataMapWales. This mapping has 5m contours and its detail matches that produced from the OS Terrain 5 product, which compliments much of that produced from LIDAR. It is this mapping that has a 413m summit height for this hill and col contouring between 385m – 390m.

Extract from the interactive DataMapWales

LIDAR summit image of Eastgate Quarry (NY 941 369)

LIDAR analysis gives this hill a summit height of 413.0m positioned at NY 94100 36976 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 413.0m and this was derived from LIDAR analysis, this is 26.0m higher than the 387m spot height that appears on the Ordnance Survey 1:50,000 Landranger map for the uppermost height leading in to this quarry, however the LIDAR height matches the rounded up height given on the interactive mapping entitled DataMapWales.

The full details for the hill are:

Group: Burnhope Seat

Name: Eastgate Quarry

OS 1:50,000 map: 91, 92

Summit Height (New Height): 413.0m (LIDAR)

Summit Grid Reference: NY 94100 36976 (LIDAR)

Col Height: 388.0m (LIDAR)

Col Grid Reference: NY 93740 36402 (LIDAR)

Drop: 24.95m (LIDAR)

Myrddyn Phillips and Aled Williams (March 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Eastgate Quarry (NY 945 371) - 16th significant height revision

Hill Reclassifications post for Eastgate Quarry

LIDAR image of Eastgate Quarry (NY 945 371)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

Extract from the Ordnance Survey 1:25,000 Explorer map

Extract from the Ordnance Survey 1:50,000 Landranger map

Extract from the interactive mapping on the WalkLakes website

Another resource now available online is the interactive mapping hosted on the Welsh Government website and entitled the DataMapWales. This mapping has 5m contours and its detail matches that produced from the OS Terrain 5 product, which compliments much of that produced from LIDAR. It is this mapping that has a 408m summit height and col contouring between 385m – 390m.

Extract from the interactive DataMapWales

LIDAR summit image of Eastgate Quarry (NY 945 371)

LIDAR analysis gives this hill a summit height of 407.5m positioned at NY 94599 37106 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 407.5m and this was derived from LIDAR analysis, this is 20.5m higher than the 387m spot height that appears on the Ordnance Survey 1:50,000 Landranger map for the uppermost height leading in to this quarry, however the LIDAR height matches the rounded up height given on the interactive mapping entitled DataMapWales.

The full details for the hill are:

Group: Burnhope Seat

Name: Eastgate Quarry

OS 1:50,000 map: 91, 92

Summit Height (New Height): 407.5m (LIDAR)

Summit Grid Reference: NY 94599 37106 (LIDAR)

Col Height: 384.9m (LIDAR)

Col Grid Reference: NY 94622 36938 (LIDAR)

Drop: 22.6m (LIDAR)

Myrddyn Phillips and Aled Williams (March 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Mid Fell (NY 580 492) - 15th significant height revision

LIDAR image of Mid Fell (NY 580 492)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Mid Fell, and it is adjoined to the Cross Fell group of hills, which are situated in the northern Pennines, and it is positioned with the B6413 road to its west and the A689 road to its east, and has the small village of Cumrew towards the west north-west.

This hill appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map without a summit spot height and with an uppermost 440m ring contour.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the height of this hill was listed as 450m with its summit positioned at NY 580 492, based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme. This map has many spot heights not on other publicly available maps and the 450m spot height is also given on the summit area of this hill.

Extract from the interactive mapping hosted on the WalkLakes website

LIDAR summit image of Mid Fell (NY 580 492)

LIDAR analysis gives the highest ground on this hill as 450.6m positioned at NY 58031 49245, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 450.6m and this was derived from LIDAR analysis, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is 10.6m higher than the uppermost 440m ring contour that appears on these maps.

The full details for the hill are:

Group: Cross Fell

Name: Mid Fell

OS 1:50,000 map: 86

Summit Height (New Height): 450.6m (LIDAR)

Summit Grid Reference: NY 58031 49245 (LIDAR)

Col Height: 423.8m (LIDAR)

Col Grid Reference: NY 58299 49034 (LIDAR)

Drop: 26.9m (LIDAR)

Myrddyn Phillips and Aled Williams (January 2023)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Lag Bank (SD 249 942) - 14th significant height revision

Summit Relocations post for Lag Bank

LIDAR image of Lag Bank (SD 249 942)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Lag Bank, and it is adjoined to the The Old Man of Coniston group of hills, which are situated in the southern fells of the Lake District, and it is positioned with a minor road to its north-west and the A593 road to its south-east, and has the village of Coniston towards the north-east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the height of this hill was listed as 411m with its summit positioned at SD 250 943, based on the spot height positioned at SD 25078 94336 which appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR analysis gives the highest ground on this hill as 411.2m positioned at SD 24996 94270, as opposed to 410.4m positioned at SD 25083 94336 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 411.2m and this was derived from LIDAR analysis, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is 11.2m higher than the uppermost 400m ring contour that appears in this position.

The full details for the hill are:

Group: The Old Man of Coniston

Name: Lag Bank

OS 1:50,000 map: 96

Summit Height (New Height): 411.2m (LIDAR)

Summit Grid Reference: SD 24996 94270 (LIDAR)

Col Height: 380.85m (LIDAR)

Col Grid Reference: SD 25214 94767 (LIDAR)

Drop: 30.3m (LIDAR)

Myrddyn Phillips and Aled Williams (December 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Ether Knott (NY 268 171) - 13th significant height revision

LIDAR image of Ether Knott (NY 268 171)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Ether Knott, and it is adjoined to the High Raise group of hills, which are situated in the central fells of the Lake District, and it is positioned with the B5289 road to its west and a minor road to its east, and has the village of Grange towards the west.

When the 1^st edition of the The Fours was published by Europeaklist in 2013, this hill was listed with a 419m summit height based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR summit image of Ether Knott (NY 268 171)

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the height of this hill was revised to 419.8m based on available LIDAR. Latest LIDAR analysis gives the highest ground on this hill as 420.1m positioned at NY 26833 17157 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 420.1m and this was derived from LIDAR analysis, this is 0.3m higher than its previously listed height and 1.1m higher than the 419m spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

The full details for the hill are:

Group: High Raise

Name: Ether Knott

OS 1:50,000 map: 89, 90

Summit Height (New Height): 420.1m (LIDAR)

Summit Grid Reference: NY 26833 17157 (LIDAR)

Col Height: 322.4m (LIDAR)

Col Grid Reference: NY 26877 15910 (LIDAR)

Drop: 97.7m (LIDAR)

Myrddyn Phillips and Aled Williams (December 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Cold Stones (SE 125 636) - 12th significant height revision

Hill Reclassifications post for Cold Stones

Summit Relocations post for Cold Stones

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill prompted by Joe Nuttall who produced a summit analysis programme using LIDAR, and then confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Cold Stones (SE 125 636)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill reclassified from the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Cold Stones, and it is adjoined to the Whernside group of hills, which are situated in the Yorkshire Dales, and it is positioned with the B6265 road to its north and a minor road to its west, and has the town of Pateley Bridge towards the east north-east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was included as a 400m Sub-Four and listed with an estimated c 26m of drop, based on an estimated c 417m summit height positioned at SE 120 641 and a 391m col height, the latter based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, with an accompanying note stating; The one that got away, or more appropriately, the one that was quarried away, as Cold Stones was once an English 400m P30, with an imperial height of 1,403ft (427.6m) recorded for the summit on the OS 1:10,560 map, with the OS enlarged Geograph map giving a height of 391m for the extant col, thereby confirming that the hill used to have 37m of drop. The summit has been quarried leaving the highpoint of the hill at c 417m (SE 120 641) on the western rim of the former summit dome, thereby reducing the drop to c 26m and relegating the hill to Sub-Four status.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR summit image of Cold Stones (SE 125 636)

LIDAR analysis gives the highest ground on this hill as 421.2m positioned at SE 12584 63663 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 421.2m and this was derived from LIDAR analysis, this is 4.2m higher than its previously listed height of c 417m which was based on interpolation of 5m contouring that appeared on the OS Maps website.

The full details for the hill are:

Group: Whernside

Name: Cold Stones

OS 1:50,000 map: 99

Summit Height (New Height): 421.2m (LIDAR)

Summit Grid Reference: SE 12584 63663 (LIDAR)

Col Height: 390.8m (LIDAR)

Col Grid Reference: SE 11773 63538 (LIDAR)

Drop: 30.4m (LIDAR)

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (November 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Weather Hill (NY 929 391) - 11th significant height revision

Hill Reclassifications post for Weather Hill

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill prompted by Joe Nuttall who produced a summit analysis programme using LIDAR, and then confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Weather Hill (NY 929 391)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Weather Hill and it is adjoined to the Burnhope Seat group of hills (Region 35, Section 35A: The Northern Pennines), and it is positioned with minor roads to its north, west and east, and the A689 road to its south, and has the town of Stanhope towards the east.

Extract from the Ordnance Survey 1:25,000 Explorer map

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme. This map has many spot heights not on other publicly available maps and for this hill a 408m spot height is given on its summit area.

Extract from the interactive mapping hosted on the WalkLakes website

LIDAR summit image of Weather Hill (NY 929 391)

LIDAR analysis gives this hill a summit height of 410.0m positioned at NY 92906 39126 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 410.0m and this was derived from LIDAR analysis, this is 2.0m higher than the 408m spot height that appears on the interactive mapping hosted on the WalkLakes website.

The full details for the hill are:

Group: Burnhope Seat

Name: Weather Hill

OS 1:50,000 map: 91, 92

Summit Height (New Height): 410.0m (LIDAR)

Summit Grid Reference: NY 92906 39126 (LIDAR)

Col Height: 389.0m (LIDAR)

Col Grid Reference: NY 93281 39255 (LIDAR)

Drop: 21.0m (LIDAR)

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (November 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Dow Low (SK 099 675) - 10th significant height revision

Hill Reclassifications post for Dow Low

LIDAR image of Dow Low (SK 099 675)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Dow Low, and it is adjoined to the Axe Edge group of hills, which are situated in The Southern Pennines (Region 36), and it is positioned with the A515 road to its north-east, and has the town of Buxton towards the north north-west.

Extract from the Ordnance Survey 1:25,000 Explorer map

Extract from the OS Maps website

LIDAR summit image of Dow Low (SK 099 675)

LIDAR analysis gives this hill a summit height of 414.9m positioned at SK 09975 67525 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 414.9m and this was derived from LIDAR analysis, this is 2.9m higher than its previously listed height of c 412m which was based on interpolation of 5m contouring that appeared on the OS Maps website.

The full details for the hill are:

Group: Axe Edge

Name: Dow Low

OS 1:50,000 map: 119

Summit Height (New Height): 414.9m (LIDAR)

Summit Grid Reference: SK 09975 67525 (LIDAR)

Col Height: 391.2m (LIDAR)

Col Grid Reference: SK 10093 67681 (LIDAR)

Drop: 23.7m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Dow Low (SK 098 678) - 9th significant height revision

Hill Reclassifications post for Dow Low

LIDAR image of Dow Low (SK 098 678)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Dow Low, and it is adjoined to the Axe Edge group of hills, which are situated in The Southern Pennines (Region 36), and it is positioned with the B5053 road to its west and the A515 road to its north-east, and has the town of Buxton towards the north north-west.

Extract from the Ordnance Survey 1:25,000 Explorer map

Extract from the OS Maps website

The prominence of this hill has been created from the quarrying activities of the Hindlow Quarry. When it was initially included as a 400m Sub-Four, imagery on Google Maps and Google Earth was examined with the conclusion that the hill is solid and stable.However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed. The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR summit image of Dow Low (SK 098 678)

LIDAR analysis gives this hill a summit height of 419.2m positioned at SK 09807 67866 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 419.2m and this was derived from LIDAR analysis, this is 3.2m higher than its previously listed height of c 416m which was based on interpolation of 5m contouring that appeared on the OS Maps website.

The full details for the hill are:

Group: Axe Edge

Name: Dow Low

OS 1:50,000 map: 119

Summit Height (New Height): 419.2m (LIDAR)

Summit Grid Reference: SK 09807 67866 (LIDAR)

Col Height: 398.0m (LIDAR)

Col Grid Reference: SK 09828 67761 (LIDAR)

Drop: 21.2m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Dow Low (SK 094 680) - 8th significant height revision

Hill Reclassifications post for Dow Low

LIDAR image of Dow Low (SK 094 680)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill reclassified from the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

Extract from the Ordnance Survey 1:25,000 Explorer map

Extract from the OS Maps website

LIDAR summit image of Dow Low (SK 094 680)

LIDAR analysis gives this hill a summit height of 430.1m positioned at SK 09419 68071 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 430.1m and this was derived from LIDAR analysis, this is 4.1m higher than its previously listed height of c 426m which was based on interpolation of 5m contouring that appeared on the OS Maps website.

The full details for the hill are:

Group: Axe Edge

Name: Dow Low

OS 1:50,000 map: 119

Summit Height (New Height): 430.1m (LIDAR)

Summit Grid Reference: SK 09419 68071 (LIDAR)

Col Height: 396.3m (LIDAR)

Col Grid Reference: SK 09251 68164 (LIDAR)

Drop: 33.8m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Long Crags (NT 955 214) - 7th significant height revision

Hill Reclassifications post for Long Crags

Summit Relocations post for Long Crags

Significant Name Changes post for Long Crags

Long Crags (NT 955 214). Photo: Aled Williams

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Long Crags, and it is adjoined to the The Cheviot group of hills, which are situated in Northumberland (Region 33: Scottish Border to the River Tyne), and it is positioned with a minor road to its north and the A697 road to its east, and has the town of Wooler towards the north north-east.

During the updating of this list for the 2^nd edition this hill was noted and listed with 18m of drop, based on the 432m summit spot height positioned at NT 95699 21058 that appears on the Ordnance Survey 1:50,000 Lanranger and 1:25,000 Explorer map and the 414m col spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR image of Long Crags (NT 955 214)

LIDAR analysis gives this hill a summit height of 439.5m positioned at NT 95597 21432 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

LIDAR summit image of Long Crags (NT 955 214)

Therefore, the new listed summit height of this hill is 439.5m and this was derived from LIDAR analysis, this is 7.5m higher than its previously listed height of 432m which appears as a spot height on the Ordnance Survey 1:50,000 Lanranger and 1:25,000 Explorer map.

The full details for the hill are:

Group: The Cheviot

Name: Long Crags

OS 1:50,000 map: 74, 75

Summit Height (New Height): 439.5m (LIDAR)

Summit Grid Reference: NT 95597 21432 (LIDAR)

Col Height: 415.8m (LIDAR)

Col Grid Reference: NT 95503 20955 (LIDAR)

Drop: 23.7m (LIDAR)

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (September 2022)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Crook (SD 664 935) - 6th significant height revision

Hill Reclassifications post for Crook

LIDAR image of Crook (SD 664 935)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Crook, and it is adjoined to the The Calf group of hills, which are situated in the Howgill Fells (Region 35, Section 35A: The Northern Pennines), and it is positioned with the B6257 road to its west, the A684 road to its south and the A683 road to its east, and has the town of Sedbergh towards the south south-west.

Extract from the Ordnance Survey 1:25,000 Explorer map

During the updating of this list for the 2^nd edition this hill was noted and listed with an estimated c 17m of drop, based on the 462m summit spot height that appears on the Harvey 1:25,000 Superwalker map to the Howgill Fells and an estimated c 445m col height based on interpolation of 10m contouring between 440m – 450m that appear on the Ordnance Survey 1:25,000 Explorer map.

Extract from the Harvey 1:25,000 Superwalker map to the Howgill Fells

LIDAR summit image of Crook

LIDAR analysis gives this hill a summit height of 464.7m positioned at SD 66458 93550 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 464.7m and this was derived from LIDAR analysis, this is 2.7m higher than its previously listed height of 462m which appears as a spot height on the Harvey 1:25,000 Superwalker map to the Howgill Fells.

The full details for the hill are:

Group: The Calf

Name: Crook

OS 1:50,000 map: 98

Summit Height (New Height): 464.7m (LIDAR)

Summit Grid Reference: SD 66458 93550 (LIDAR)

Col Height: 444.4m (LIDAR)

Col Grid Reference: SD 66410 93726 (LIDAR)

Drop: 20.3m (LIDAR)

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (September 2021)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Low Fell (NY 135 222) - 5th significant height revision

Hill Reclassifications post for Low Fell

LIDAR image of Low Fell (NY 135 222)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Low Fell, and it is adjoined to the Great Gable group of hills, which are situated in the Lake District (Region 34, Section 34B: The Central and Western Fells), and it is positioned with the A5086 road to its north-west, a minor road to its south and the B5289 road to its north-east, and has the small community of Brackenthwaite towards the east.

During the updating of this list for the 2^nd edition this hill was noted and listed with an estimated c 13m of drop, based on the 412m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 399m col height based on interpolation of 10m contouring between 390m – 400m.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR analysis gives this hill a summit height of 417.1m positioned at NY 13598 22260 and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, this hill’s new listed summit height is 417.1m and this was derived from LIDAR analysis, this is 5.1m higher than its previously listed height of 412m which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Great Gable

Name: Low Fell

OS 1:50,000 map: 89

Summit Height (New Height): 417.1m (LIDAR)

Summit Grid Reference: NY 13598 22260 (LIDAR)

Col Height: 395.5m (LIDAR)

Col Grid Reference: NY 13659 22371 (LIDAR)

Drop: 21.6m (LIDAR)

Our thanks to Ronnie Bowron for bringing the details of this hill to our attention

Myrddyn Phillips and Aled Williams (August 2021)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Green Side (NT 906 076) - 4th significant height revision

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops. The resulting spreadsheet that Joe produced contains over 29600 hills.

This spreadsheet is being evaluated by DoBIH Editors and others, and for this particular hill it was Jim Bloomer who initially assessed its height and that of its adjacent peak via LIDAR analysis.

Myrddyn Phillips then evaluated this hill’s details via LIDAR analysis and confirmed its height revision, summit relocation and addition as a 390m Sub-Four.

LIDAR image of Green Side (NT 906 076)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being added to the 390m Sub-Four category, the criteria for which are all English hills at or above 390m and below 400m in height that have 30m minimum drop. The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Green Side, and it is adjoined to The Cheviot group of hills, which are situated in the north-eastern part of England (Region 33 Scottish Border to the River Tyne), and it is positioned with a minor road to its south-east and farther afield has the A68 road to its south-west, the B6341 road to its south-east and the A697 road to its east, and has the town of Rothbury towards the east south-east.

When the 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was not classified but was listed with an estimated c 17m of drop, based on the 389m summit height adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and an estimated c 372 col height based on interpolation of 5m contouring between 370m – 375m that appear on the OS Maps website.

Extract from the Ordnance Survey 1:25,000 Explorer map

Approximately 1km to the north-east of the triangulation pillar atop Green Side is the hill named Lord’s Seat. The flush bracket adjoined to this trig pillar is given as 389.534m and positioned at NT 90299 07313 in the OS Trig Database, with its map height given as 389m. As the map height of Lord’s Seat is 392m it was this hill that was classified as the 390m Sub-Four with c 53m of drop.

However, it was not until LIDAR became available that the details for these two hills could be accurately re-assessed. The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

The summit height produced by LIDAR analysis for these two hills is given below:

Lord’s Seat: 392.2m at NT 91281 07968 and NT 91282 07966

Green Side: 395.5m at NT 90695 07602

The above detail comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated summit height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR. Also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

LIDAR summit image of Green Side

Therefore, this hill’s new listed summit height is 395.5m and this was derived from LIDAR analysis, this is 6.5m higher compared to its previously listed summit height of 389m which is adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and 3.5m higher than the 392m spot height given the previous qualifying hill of Lord’s Seat.

The full details for the hill are:

Group: The Cheviot

Name: Green Side

OS 1:50,000 map: 80

Summit Height (New Height): 395.5m (LIDAR)

Summit Grid Reference: NT 90695 07602 (LIDAR)

Col Height: 339.5m (LIDAR)

Col Grid Reference: NT 90531 07919 (LIDAR)

Drop: 56.0m (LIDAR)

Myrddyn Phillips and Aled Williams (August 2020)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Black Hill (SX 761 786) - 3rd significant height revision

LIDAR image of Black Hill (SX 761 786)

The criteria for the list this height revision affects are:

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Black Hill, and it is adjoined to the Broad Barrow group of hills, which are situated in Dartmoor in the south-west of the country, and it is positioned with the A382 road to its north-east and the A38 road to its south south-east, and has the village of Widecombe-in-the-Moor to the west south-west and the town of Bovey Tracey to the east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with an estimated c 31m of drop, based on the 412m summit spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map and an estimated c 381m col height, based on interpolation of 10m contouring between 380m – 390m.

Extract from the Ordnance Survey 1:25,000 Explorer map

LIDAR summit image of Black Hill (SX 761 786)

LIDAR analysis gives the highest ground on this hill as 414.2m positioned at SX 76101 78646, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 414.2m and this was derived from LIDAR analysis, this is 2.2m higher than its previously listed height of 412m which appears as a spot height on the Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Broad Barrow

Name: Black Hill

OS 1:50,000 map: 191

Summit Height (New Height): 414.2m (LIDAR)

Summit Grid Reference: SX 76101 78646 (LIDAR)

Col Height: 381.0m (LIDAR)

Col Grid Reference: SX 75841 77803 (LIDAR)

Drop: 33.2m (LIDAR)

Myrddyn Phillips and Aled Williams (June 2018)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Tindale Law (NT 859 108) - 2nd significant height revision

There has been a Significant Height Revision to a hill that is listed in The Fours initiated by LIDAR analysis conducted by Myrddyn Phillips. The Fours is the title for the list of 400m hills of England and is co-authored by Myrddyn Phillips and Aled Williams with the 2^nd edition of the booklet containing this list published by Mapping Mountains Publications on the 24.04.18.

The criteria for the list that this significant height revision affects are:

The Fours - English hills at and above 400m and below 500m in height that have a minimum 30m of drop.

The name of the hill is Tindale Law and it is situated in Region 33; Scottish Border to the River Tyne, and is positioned overlooking the River Coquet which is to its west, north and east and has the small community of Barrowburn towards the east.

As the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a public footpath crosses near to the critical col and the summit is then only a short distance to the north.

Prior to LIDAR analysis this hill was listed with 60m of drop based on the 423m summit and 363m col spot height that appear on the Ordnance Survey Interactive Coverage Map hosted on the Geograph.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The summit height produced by LIDAR analysis is 420.959m, this is not a dramatic height revision when compared to some revised heights, but it does come within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or by LIDAR analysis, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by analysis of LIDAR. As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these revisions.

Therefore, this hill’s new summit height is 421.0m and this was produced by LIDAR analysis, this is 2.0m lower than its previously listed height of 423m which appears as a spot height on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

The full details for the hill are:

Cardinal Hill: Thirl Moor

Summit Height (New Height): 421.0m (LIDAR)

Name: Tindale Law

OS 1:50,000 map: 80

Summit Grid Reference: NT 85953 10829 (LIDAR)

Drop: 58.5m (LIDAR)

Myrddyn Phillips and Aled Williams (May 2018)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Minton Hill (SO 414 919) - 1st significant height revision

Survey post for Minton Hill

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with these details being retrospective as the survey that resulted in this height revision was conducted on 2^nd January 2015. With the summit height, col height and their locations, the drop and status of the hill derived from a Trimble GeoXH 6000 survey and subsequent LIDAR analysis conducted by Myrddyn Phillips.

Minton Hill (SO 414 919)

The criteria for the list this height revision affects are:

The Fours – The 400m Hills of England. English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams, with the 1^st edition of the booklet containing this list published by Europeaklist in December 2013 and by Haroldstreet in January 2014.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Minton Hill and it is adjoined to the Stiperstones group of hills, which are situated in the county of Shropshire close to the Welsh border, and it is positioned by minor roads to its north-west and south-east, with the A489 road to its south-west and the B5477 road and the A49 road to its east, and has the town of Church Stretton towards the east north-east.

Extract from the Ordnance Survey 1:25,000 Explorer map

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with 22m of drop, based on the 453m summit spot height and the 453m col spot height that appear on the contemporary Ordnance Survey 1:25,000 Explorer map.

The Trimble GeoXH 6000 gathering data at the summit of Minton Hill

However, it was not until the survey with the Trimble GeoXH 6000 that an accurate height could be established for the summit of this hill. This survey gives the highest ground on this hill as 455.4m positioned at SO 41456 91920, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Therefore, the new listed summit height of this hill is 455.4m and this was derived from a Trimble GeoXH 6000 survey, this position is adjacent to where the spot height appears and is 2.4m higher than the previously listed 453m summit height, which appears as a spot height on the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Stiperstones

Name: Minton Hill

OS 1:50,000 map: 137

Summit Height: 455.4m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference: SO 41456 91920 (Trimble GeoXH 6000)

Col Height: 431.9m (LIDAR)

Col Grid Reference: SO 41252 92137 (LIDAR)

Drop: 23.5m (Trimble GeoXH 6000 summit and LIDAR col)

Myrddyn Phillips and Aled Williams (September 2015)

Thursday 26 October 2017

Mapping Mountains – Significant Height Revisions – The Fours - The 400m Hills of England

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