Mapping Mountains – Summit Relocations – Y Pellennig – The Remotest Hills of Wales

Graig Wen (SN 786 629) 

There has been a Summit Relocation to a hill that is listed in the Y Pellennig – The Remotest Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Graig Wen (SN 786 629)

The criteria for the list that this summit relocation applies to are:

Y Pellennig –The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet or print-booklet version on Mapping Mountains Publications with the up-to-date master list available on Mapping Mountains to download in Google Doc format. 

Y Pellennig - The Remotest Hills of Wales by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Graig Wen, and this was derived from local enquiry and it is adjoined to the Esgair Wen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north-west and the B4343 road farther to its north-west, and has the village of Pontrhydfendigaid also towards the north-west.

When the listing that became known as the Y Pellennig – The Remotest Hills of Wales was first compiled, this hill was listed with an estimated c 16m of drop, based on the 479m summit spot height positioned at SN 78618 62909 that appears on the Ordnance Survey 1:25,000 Explorer map, and an estimated c 463m bwlch height, based on interpolation of 10m contouring between 460m – 470m. 

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 analysis gives the highest ground on this hill as 479.3m positioned at SN 78613 62923.  However, this is to the top of what LIDAR indicates is a raised ridge line of trees 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 o Graig Wen (SN 786 629)

The summit area of this hill is intermittently covered by conifer plantation and therefore this whole area has been disturbed by man, however the height produced by LIDAR analysis to the highest centralised contour and to what could be deemed the natural summit of this hill is 479.2m and is positioned at SN 78619 62908, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour either on Ordnance Survey maps or interactive mapping, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill 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 the listing of a new twin summit or de-twinning of a summit, 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 new listed summit height of this hill is 479.2m and this is positioned at SN 78619 62908 and this was derived from LIDAR analysis, this position is approximately 15 metres south south-eastward from where the high point of the raised line of trees is positioned.

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Esgair Wen

Name:  Graig Wen

OS 1:50,000 map:  146, 147

Summit Height:  479.2m (LIDAR) 

Summit Grid Reference (New Position):  SN 78619 62908 (LIDAR) 

Bwlch Height:  459.9m (LIDAR) 

Bwlch Grid Reference:  SN 78426 63149 (LIDAR) 

Drop:  19.3m (LIDAR) 

Remoteness:  3.000km

 

Myrddyn Phillips and Aled Williams (February 2026) 

Mapping Mountains – Summit Relocations – Y Pellennig – The Remotest Hills of Wales, Welsh Highlands – Uchafion Cymru and 900m Twmpau

 

Foel Fras (SH 696 681) 

There has been a Summit Relocation to a hill that is listed in the Y Pellennig – The Remotest Hills of Wales, Welsh Highlands – Uchafion Cymru and 900m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Leica RX1250 survey conducted by Alan Dawson. 

Foel Fras (SH 696 681) from the summit of Trwsgl (SH 663 679)

The criteria for the three listings that this summit relocation applies to are:

Y Pellennig –The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet or print-booklet version on Mapping Mountains Publications with the up-to-date master list available on Mapping Mountains to download in Google Doc format. 

Y Pellennig - The Remotest Hills of Wales by Myrddyn Phillips and Aled Williams

Welsh Highlands – Uchafion Cymru – Welsh hills at or above 500m in height with 15m minimum drop, with an accompanying sub list entitled the Welsh Highland Subs, the criteria for which is all Welsh hills at or above 500m in height with 10m or more and below 15m of drop.  This list is authored by Myrddyn Phillips and Aled Williams with the Introduction to the list published on Mapping Mountains in November 2015 and the latest update relating to the list published on Mapping Mountains in January 2023.

Welsh Highlands - Uchafion Cymru by Aled Williams and Myrddyn Phillips

900m Twmpau - Welsh hills at or above 900m and below 1000m in height with 30m minimum drop, with an accompanying sub list entitled the 900m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 900m and below 1000m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.  The list is authored by Myrddyn Phillips and is available to download in Google Doc format from Mapping Mountains.

900m Twmpau by Myrddyn Phillips

The name the hill is listed by is Foel Fras and it is adjoined to the Carnedd Llywelyn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A55 road to its north-west, the A5 road to its south-west and the B5106 and A470 roads to its east, and has the town of Bethesda towards the west south-west. 

When the original list that later became known as the Welsh Highlands – Uchafion Cymru was first compiled, this hill was listed with 58m of drop, based on the 942m summit spot height adjoined to a triangulation pillar positioned at SH 69652 68173 that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and the 884m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

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

However, the summit area of this hill is rocky and includes a number of substantial upright rock spikes.  One of the earliest Abney Level surveys to ascertain the high point of this hill was conducted in 2011 by Graham Jackson.  This survey concluded that a rock spike approximately 55 metres south-wesward of the trig pillar is the highest point of this hill. 

This rock spike was subsequently surveyed by Alan Dawson using the Leica RX1250, resulting in a 944.1m summit height positioned at SH 69611 68118, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill 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.

The Leica RX1250 gathering data at the summit of Foel Fras (SH 696 681).  Photo: Alan Dawson  

Therefore, the new listed summit height of this hill is 944.1m and this is positioned at SH 69611 68118 and this was derived from a Leica RX1250 survey, this position is approximately 55 metres south-westward from where the triangulation pillar is positioned and importantly it is positioned to a different feature.

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Carnedd Llywelyn

Name:  Foel Fras

OS 1:50,000 map:  115

Summit Height:  944.1m (converted to OSGM15, Leica RX1250) 

Summit Grid Reference (New Position):  SH 69611 68118 (Leica RX1250) 

Bwlch Height:  881.3m (converted to OSGM15, Leica RX1250) 

Bwlch Grid Reference:  SH 68799 66515 (Leica RX1250) 

Drop:  62.8m (Leica RX1250) 

Remoteness:  3.975km

 

Myrddyn Phillips and Aled Williams (August 2024)

 

Mapping Mountains – Summit Relocations – 30-99m Twmpau, Y Trechol – The Dominant Hills of Wales and Y Pellennig – The Remotest Hills of Wales

DUE TO SUBSEQUENT LIDAR ANALYSIS THE SUMMIT POSITION OF THIS HILL HAS BEEN RELOCATED TO SM 72972 04697

The Head (SM 731 046) 

There has been a Summit Relocation to a hill that is listed in the 30-99m Twmpau, Y Trechol – The Dominant Hills of Wales and Y Pellennig – The Remotest Hills of Wales, with the summit height and its location, the drop, dominance, remoteness and status of the hill prompted by detail produced by Joe Nuttall in his surface analysis programme (JNSA). 

The criteria for the three listings that this summit relocation applies to are: 

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height that have 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

30-99m Twmpau by Myrddyn Phillips

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

Y Pellennig – The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has 15m minimum drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet and print-booklet version on Mapping Mountains Publications with the up-to-date master list available to download on the Mapping Mountains site in Google Doc format.

Y Pellennig - The Remotest Hills of Wales by Myrddyn Phillips and Aled Williams

The name the hill is listed by is The Head, and it is adjoined to the Garn Fawr group of hills which are situated in the south-western part of South Wales (Region B, Sub-Region B1), and it is positioned on the island of Skokholm which is positioned to the south-west of the Pembrokeshire coast.

When the original 30-99m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list with a 55m summit height positioned at SM 730 047, with an accompanying note stating; Height from 1:10000 map, details from David Purchase.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 56m summit height and drop, based on interpolation of its largest 55m uppermost contour positioned at SM 72969 04698.  The summit position was subsequently and slightly amended to SM 72970 04701 from detail that appeared on the Hill Bagging website. 

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

However, it was not until Joe Nuttall developed his surface analysis programme that the details of this hill could be analysed via the OS Terrain product.  The height produced by the surface analysis programme is 55.0m and this is positioned at SM 73112 04672, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be 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 height produced by the surface analysis programme developed by Joe Nuttall is 55.0m and is positioned at SM 73112 04672, 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 55m contour and approximately 42 metres eastward from where the previously listed summit is positioned. 

 

The full details for the hill are: 

Group:  Garn Fawr

Name:  The Head

OS 1:50,000 map:  157

Summit Height:  55.0m (JNSA)

Summit Grid Reference (New Position):  SM 73112 04672 (JNSA)

Bwlch Height:  N/A (island)

Bwlch Grid Reference:  N/A (island)

Drop:  55.0m (JNSA)

Dominance:  100.00% (island)

Remoteness:  5.21km (JNSA)

 

Myrddyn Phillips and Aled Williams (May 2024)

 

  

Mapping Mountains – Summit Relocations – Welsh Highlands – Uchafion Cymru and Y Pellennig – The Remotest Hills of Wales

Esgair Llyn Du (SN 769 620) 

There has been a Summit Relocation to a hill that is listed in the Welsh Highlands – Uchafion Cymru and Y Pellennig – The Remotest Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Aled Williams. 

Esgair Llyn Du (SN 769 620)

The criteria for the two listings that this summit relocation applies to are:

Welsh Highlands – Uchafion Cymru – Welsh hills at or above 500m in height with 15m minimum drop, with an accompanying sub list entitled the Welsh Highland Subs, the criteria for which is all Welsh hills at or above 500m in height with 10m or more and below 15m of drop.  This list is authored by Myrddyn Phillips and Aled Williams with the Introduction to the list published on Mapping Mountains in November 2015 and the latest update relating to the list published on Mapping Mountains in January 2023.

Welsh Highlands - Uchafion Cymru by Aled Williams and Myrddyn Phillips

Y Pellennig – The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has 15m minimum drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet and print-booklet version on Mapping Mountains Publications with the up-to-date master list available to download on the Mapping Mountains site in Google Doc format.

Y Pellennig - The Remotest Hills of Wales by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Esgair Llyn Du and it is adjoined to the Esgair Wen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its north-west and south, and has the small community of Pontrhydfendigaid towards the north-west and the town of Tregaron towards the west south-west. 

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

When the 1^st edition of the Y Pellennig – The Remotest Hills of Wales was published by Europeaklist in April 2015, this hill was listed with 3.075km of remoteness and 20m of drop, based on the 534m summit spot height positioned at SN 767 617 and the 514m bwlch spot heights that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, with this mapping giving two positions of equal height for the bwlch. 

Extract from the interactive mapping hosted on the WalkLakes website

The Ordnance Survey Vector Map Local hosted on the Geograph website gave the higher spot height to the middle of three larger 530m map contour rings, with the southerly and middle ring contours subsequently surveyed with the Trimble GeoXH 6000.  However, the interactive mapping hosted on the WalkLakes website indicates that the most northerly of these is the higher. 

The Trimble GeoXH 6000 set-up position at the southerly of the three tops

The Trimble GeoXH 6000 set-up position at the central of the three tops

At the northerly of the three tops and the summit of Esgair Llyn Du

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. 

 

The results from these surveys are given below: 

LIDAR for northerly summit:  532.849m at SN 76930 62044 

LIDAR for central summit:  532.729m at SN 76768 61773 

Trimble GeoXH 6000 for central summit:  532.552m at SN 76770 61772 

LIDAR for southerly summit:  532.020m at SN 76691 61642 

Trimble GeoXH 6000 for southerly summit:  531.914m at SN 76691 61642 

 

The 532.8m summit height produced by LIDAR analysis and its position in relation to the previously listed summit 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. 

LIDAR image of Esgair Llyn Du (SN 769 620)

LIDAR summit image of Esgair Llyn Du (SN 769 620)

Therefore, the summit height produced by LIDAR analysis is 532.8m and this is positioned at SN 76930 62044.  This position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, but a 532m spot height appears in this position on the interactive mapping hosted on the WalkLakes website and is approximately 440 metres north-eastward from where the originally listed summit is positioned and approximately 300 metres north-eastward from where the previously listed summit is positioned, resulting in its remoteness being amended from 3.075km to 2.925km.

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Esgair Wen

Name:  Esgair Llyn Du

OS 1:50,000 map:  146, 147

Summit Height:  532.8m (LIDAR) 

Summit Grid Reference:  SN 76930 62044 (LIDAR) 

Bwlch Height:  513.8m (LIDAR) 

Bwlch Grid Reference:  SN 76942 61196 (LIDAR) 

Drop:  19.0m (LIDAR) 

Remoteness:  2.925 km

 

Myrddyn Phillips and Aled Williams (November 2023)