Myrddyn Phillips - Mapping Mountains: Mapping Mountains – Summit Relocations

The Fours – The 400m Hills of England – Summit Relocations

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 Summit Relocations 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 - Summit Relocations - The Fours - The 400m Hills of England
Blackkip (NT 799 043) - 45th summit relocation
Hill Reclassifications post for Blackkip
Significant Height Revisions post for Blackkip

There has been a Summit Relocation to a hill 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 summit relocation 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 highest ground on this hill as 448.6m positioned at NT 79958 04358, and when compared to its originally listed summit position this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 448.6m and this is positioned at NT 79958 04358. 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 approximately 140 metres north-eastward from where the originally listed summit is positioned.

The full details for the hill are:
Group: Thirl Moor
Name: Blackkip
OS 1:50,000 map: 80
Summit Height: 448.6m (LIDAR)
Summit Grid Reference (New Position): 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 (November 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 - Summit Relocations - The Fours - The 400m Hills of England

South Hessary Tor (SX 597 723) - 44th summit relocation

Significant Height Revisions post for South Hessary Tor

Significant Name Changes post for South Hessary Tor

There has been a Summit Relocation 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 South Hessary Tor (SX 597 723)

The criteria for the list that this summit relocation 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 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 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

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 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 Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to when the high point is positioned in a different field, to a different feature such as a conifer plantation, within a different map contour, a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the summit height produced by LIDAR analysis is 454.1m and this is positioned at SX 59712 72361. 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 approximately 700 metres south south-eastward from where the originally listed summit is positioned.

The full details for the hill are:

Group: High Willhays

Name: South Hessary Tor

OS 1:50,000 map: 191

Summit Height: 454.1m (LIDAR)

Summit Grid Reference (New Position): 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 (March 2024)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Royal Hill (SX 606 733) - 43rd summit relocation

There has been 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 initially conducted by Aled Williams and subsequently by Myrddyn Phillips.

LIDAR image of Royal Hill (SX 606 733)

The criteria for the list that this summit relocation 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 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 Royal Hill, 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 B3357 road to its north-east, the B3212 road to its north-west and a minor road to its south-west, and has the village of Princetown towards the west north-west.

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 21m of drop, based on the 413m summit spot height positioned at SX 61197 72800 and the 392m col spot height, both of which appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, and this is also the position the summit was listed as when the 2^nd edition of The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018.

However, it was not until the latest LIDAR became available that the details for this hill could again 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 Royal Hill (SX 606 733)

Using the latest 1m DSM LIDAR model gives the top positioned at SX 61170 71814 as 412.060m in height and the summit positioned at SX 60699 73336 as 412.111m in height, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the summit height produced by LIDAR analysis is 412.1m and this is positioned at SX 60699 73336. This position is given a 412m spot height on the contemporary Ordnance Survey 1:25,000 Explorer map and is approximately 520 metres north-westward from where the previously listed summit is positioned.

The full details for the hill are:

Group: High Willhays

Name: Royal Hill

OS 1:50,000 map: 191

Summit Height: 412.1m (LIDAR)

Summit Grid Reference (New Position): SX 60699 73336 (LIDAR)

Col Height: 391.2m (LIDAR)

Col Grid Reference: SX 60181 72633 (LIDAR)

Drop: 20.9m (LIDAR)

Myrddyn Phillips and Aled Williams (February 2024)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

North Molton Ridge (SS 778 325) - 42nd summit relocation

LIDAR image of North Molton Ridge (SS 778 325)

The criteria for the list that this summit relocation 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 are three categories of sub hills; the 400m Sub-Fours, the 390m Sub-Fours and the 390m Double Sub-Fours. 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 North Molton Ridge, and it is adjoined to the Dunkery Beacon group of hills, which are situated in the counties of Somerset and Devon, and it is positioned encircled by minor roads, with the A399 road farther to its west, the A361 road and the B3227 road farther to its south, and has the town of South Molton towards the south-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 56m of drop, based on the 435m summit spot height adjoined to a triangulation pillar that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map that is atop an ancient tumulus and which is positioned at SS 77968 32459, and an estimated c 379m col height, based on interpolation of 10m contouring between 370m – 380m.

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

LIDAR summit image of North Molton Ridge (SS 778 325)

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the details for this hill had been analysed via LIDAR and its summit relocated to a different tumulus. Latest LIDAR analysis gives the highest ground on this hill as 435.1m positioned at SS 77838 32544 and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the summit height produced by LIDAR analysis is 435.1m and this is positioned at SS 77838 32544. 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 positioned to a different feature and is approximately 130 metres north-westward from where the originally listed summit is positioned.

The full details for the hill are:

Group: Dunkery Beacon

Name: North Molton Ridge

OS 1:50,000 map: 180

Summit Height: 435.1m (LIDAR)

Summit Grid Reference (New Position): SS 77838 32544 (LIDAR)

Col Height: 381.8m (LIDAR)

Col Grid Reference: SS 77925 33972 (LIDAR)

Drop: 53.3m (LIDAR)

Myrddyn Phillips and Aled Williams (February 2024)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Wood Barrow (SS 716 425) - 41st summit relocation

Significant Name Changes post for Wood Barrow

LIDAR image of Wood Barrow (SS 716 425)

The criteria for the list that this summit relocation 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 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 Wood Barrow, and it is adjoined to the Dunkery Beacon group of hills, which are situated in the counties of Somerset and Devon, and it is positioned with the A39 road to its north-west and the B3358 road to its south, and has the small community of Parracombe towards the west north-west.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, the qualifying 400m Sub-Four hill was listed as Wood Barrow (SS 716 425) with 22m of drop, based on the 480m summit spot height that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and the 458m col spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating:

Although Chapman Barrows at SS 700 434 has a 480m map height, it is not listed as a twin Sub-Four as its 480.093m flush bracket height means ground at the base of the trig pillar will be below 480m.

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

LIDAR image of Chapman Barrows (SS 700 434) and Wood Barrow (SS 716 425)

The height produced by initial LIDAR analysis to the high point of Chapman Barrows is 479.8m positioned at SS 70003 43472 and to the high point of Wood Barrow is 479.7m positioned at SS 71627 42506, resulting in the summit of the qualifying 400m Sub-Four being relocated from Wood Barrow to Chapman Barrows.

LIDAR summit image of Wood Barrow (SS 716 425)

However, the latest available LIDAR analysis gives the high point of Chapman Barrows as 479.8m positioned at SS 70003 43471 and the high point of Wood Barrow as 480.0m positioned at SS 71627 42505, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the height produced by the latest available LIDAR analysis to the summit of Wood Barrow is 480.0m and this is positioned at SS 71627 42505. This position is adjacent to where the 480m spot height appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 1.8km south-eastward from the summit of Chapman Barrows which LIDAR gives as 0.2m lower.

The full details for the hill are:

Group: Dunkery Beacon

Name: Wood Barrow

OS 1:50,000 map: 180

Summit Height: 480.0m (LIDAR)

Summit Grid Reference (New Position): SS 71627 42505 (LIDAR)

Col Height: 457.7m (LIDAR)

Col Grid Reference: SS 72621 42582 (LIDAR)

Drop: 22.3m (LIDAR)

Myrddyn Phillips and Aled Williams (January 2024)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Betchcott Hill (SO 421 982) - 40th summit relocation

Survey post for Betchcott Hill

There has been confirmation of 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 Betchcott Hill (SO 421 982)

The criteria for the list that this summit relocation 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 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 Betchcott 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 encircled by minor roads, with the A488 road farther to its north-west and the A49 road farther to its east, and has the town of Church Stretton towards the south-east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with 20m of drop and with a 414m summit height based on the spot height that appears on the contemporary Ordnance Survey 1:25,000 Explorer map and which is positioned at SO 420 982. 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 had been surveyed with the Trimble GeoXH 6000, resulting in a 414.3m summit height positioned at SO 420 982.

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

However, it was not until LIDAR became available that the details for the summit of 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.

The raised field boundary on the summit of Betchcott Hill

LIDAR analysis gives the highest ground on this hill as 414.3m positioned at SO 42097 98234. However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill.

LIDAR summit image of Betchcott Hill (SO 421 982)

The height produced by LIDAR analysis to the natural summit of this hill is 414.2m positioned at SO 42106 98231, and this position in relation to the raised field boundary comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the summit height produced by LIDAR analysis is 414.2m and this is positioned at SO 42106 98231. This position is close to where the 414m summit spot height appears on the contemporary Ordnance Survey 1:25,000 Explorer map and is approximately 9 metres eastward from the high point of the raised field boundary.

The full details for the hill are:

Group: Stiperstones

Name: Betchcott Hill

OS 1:50,000 map: 137

Summit Height: 414.2m (LIDAR)

Summit Grid Reference (New Position): SO 42106 98231 (LIDAR)

Col Height: 394.3m (LIDAR)

Col Grid Reference: SO 42922 97926 (LIDAR)

Drop: 20.0m (LIDAR)

Myrddyn Phillips and Aled Williams (December 2023)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Dowke Hill (SO 224 806) - 39th summit relocation

LIDAR image of Dowke Hill (SO 224 806)

The criteria for the list that this summit relocation 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 are three categories of sub hills; the 400m Sub-Fours, the 390m Sub-Fours and the 390m Double Sub-Fours. 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 Dowke Hill, and it is adjoined to the Cilfaesty 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 B4368 road farther to its north, the B4355 road farther to its south-west and the A488 road farther to its east south-east, and has the town of Clun towards 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 33m of drop and with a 416m summit height positioned at SO 224 806. 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 had been analysed via LIDAR, resulting in a 417.0m summit height positioned at SO 224 806.

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

However, it was not until the latest LIDAR coverage became available that other numerical 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 analysis gives the highest ground on this hill as 417.4m positioned at SO 22452 80672. However, this is a part of a hedge incorporated in a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill.

LIDAR summit image of Dowke Hill (SO 224 806)

The height produced by the latest LIDAR analysis to the natural summit of this hill is 417.2m positioned at SO 22447 80675, and this position in relation to the raised field boundary comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the summit height produced by the latest LIDAR analysis is 417.2m and this is positioned at SO 22447 80675. This position is close to where the 416m spot height appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 5 metres westward from the high point of the hedge incorporated in the raised field boundary.

The full details for the hill are:

Group: Cilfaesty

Name: Dowke Hill

OS 1:50,000 map: 137

Summit Height: 417.2m (LIDAR)

Summit Grid Reference (New Position): SO 22447 80675 (LIDAR)

Col Height: 383.6m (LIDAR)

Col Grid Reference: SO 21653 80934 (LIDAR)

Drop: 33.5m (LIDAR)

Myrddyn Phillips and Aled Williams (December 2023)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Bryn Hill (SO 295 862) - 38th summit relocation

Survey post for Bryn Hill

There has been confirmation via LIDAR analysis of 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 a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.

LIDAR image of Bryn Hill (SO 295 862)

The criteria for the list that this summit relocation 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 are three categories of sub hills; the 400m Sub-Fours, the 390m Sub-Fours and the 390m Double Sub-Fours. 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 Bryn Hill, and it is adjoined to the Cilfaesty 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-west and south, with the A488 road to its east, and has the town of Bishop’s Castle towards the north-east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with 109m of drop and with a 408m summit height positioned at SO 294 862. When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, the hill had been surveyed with the Trimble GeoXH 6000, resulting in a 407.5m summit height positioned at SO 295 862.

The Trimble GeoXH 6000 gathering data at the natural summit of Bryn Hill

However, although the natural summit of this hill has been surveyed with the Trimble GeoXH 6000 it was not until LIDAR became available that other numerical 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 Bryn Hill (SO 295 862)

LIDAR analysis gives the highest ground on this hill as 408.9m positioned at SO 29494 86204. However, this is a part of a raised field boundary that incorporates a water tank and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill.

The height produced by the Trimble GeoXH 6000 survey to the natural summit of this hill is 407.5m positioned at SO 29550 86222, and this position in relation to the raised field boundary and water tank comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 407.5m and this is positioned at SO 29550 86222. 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 approximately 56 metres eastward from the high point of the raised field boundary incorporating the water tank which is where the 408m spot height appears on the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group: Cilfaesty

Name: Bryn Hill

OS 1:50,000 map: 137

Summit Height: 407.5m (Trimble GeoXH 6000)

Summit Grid Reference (New Position): SO 29550 86222 (Trimble GeoXH 6000)

Col Height: 298.9m (Trimble GeoXH 6000)

Col Grid Reference: SO 29299 86584 (Trimble GeoXH 6000)

Drop: 108.6m (Trimble GeoXH 6000)

Myrddyn Phillips and Aled Williams (December 2023)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Reilth Top (SO 284 881) - 37th summit relocation

Hill Reclassifications post for Reilth Top

Survey post for Reilth Top

Reilth Top (SO 284 881)

The criteria for the list that this summit relocation 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 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 Reilth Top, and it is adjoined to the Cilfaesty 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 B4385 road farther to its north, the A489 road farther to its north-west, the B4368 road farther to its south and the A488 road farther to its east, and has the town of Bishop’s Castle towards 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 30m of drop and with an estimated c 406m summit height positioned at SO 284 881, and it was this position that was also given for the summit of this hill when the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, with the drop value being amended to 29.3m.

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

However, although the natural summit of this hill has been surveyed with the Trimble GeoXH 6000 it was not until LIDAR became available that the other numerical 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.

The Trimble GeoXH 6000 gathering data at the natural summit of Reilth Top

The raised field boundary

LIDAR analysis gives the highest ground on this hill as 405.0m positioned at SO 28427 88095. However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill.

LIDAR image of Reilth Top (SO 284 881)

The height produced by the Trimble GeoXH 6000 survey to the natural summit of this hill is 404.6m positioned at SO 28458 88105, and this position in relation to the raised field boundary comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

LIDAR summit image of Reilth Top (SO 284 881)

Therefore, the summit height produced by the Trimble GeoXH 6000 survey is 404.6m and this is positioned at SO 28458 88105. This position is given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger map and is within the uppermost 405m contour ring that appears on the 1:25,000 Explorer map and is approximately 30 metres eastward from the high point of the raised field boundary.

The full details for the hill are:

Group: Cilfaesty

Name: Reilth Top

OS 1:50,000 map: 137

Summit Height: 404.6m (Trimble GeoXH 6000)

Summit Grid Reference (New Position): SO 28458 88105 (Trimble GeoXH 6000)

Col Height: 375.4m (LIDAR)

Col Grid Reference: SO 28878 87840 (LIDAR)

Drop: 29.2m (Trimble GeoXH 6000 summit and LIDAR col)

Myrddyn Phillips and Aled Williams (December 2023)

Mapping Mountains - Summit Relocations - The Fours - The 400m Hills of England

Hergan (SO 262 853) - 36th summit relocation

LIDAR image of Hergan (SO 262 853)

The criteria for the list that this summit relocation 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 are three categories of sub hills; the 400m Sub-Fours, the 390m Sub-Fours and the 390m Double Sub-Fours. 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 Hergan, and it is adjoined to the Cilfaesty 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 B4368 road farther to its south and the A488 road farther to its east, and has the town of Clun towards the south-east.

When the 1^st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed with 50m of drop with a 409m summit height positioned at SO 263 853, and it was this position that was also given for the summit of this hill 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

LIDAR analysis gives the highest ground on this hill as 409.0m positioned at SO 26308 85354. However, this is a part of a sunken water tank and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill.

LIDAR summit image of Hergan (SO 262 853)

The height produced by LIDAR analysis to the natural summit of this hill is 408.9m positioned at SO 26298 85342 and SO 26297 85345, and this position in relation to the sunken water tank comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

Therefore, the summit height produced by LIDAR analysis is 408.9m and this is positioned at SO 26298 85342 and SO 26297 85345. This position is given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 12 metres south-westward from the high point of the sunken water tank.

The full details for the hill are:

Group: Cilfaesty

Name: Hergan

OS 1:50,000 map: 137

Summit Height: 408.9m (LIDAR)

Summit Grid Reference (New Position): SO 26298 85342 & SO 26297 85345 (LIDAR)

Col Height: 358.5m (LIDAR)

Col Grid Reference: SO 26112 85472 (LIDAR)

Drop: 50.4m (LIDAR)

Myrddyn Phillips and Aled Williams (November 2023)

Wednesday, 6 December 2023

Mapping Mountains – Summit Relocations – The Fours - The 400m Hills of England

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