Thursday, 13 July 2017

Mapping Mountains – Hill Reclassifications – Y Pedwarau


Y Pedwarau – Hill Reclassifications

Y Pedwarau are the Welsh hills at or above 400m and below 500m in height that have a minimum drop of 30m.  Accompanying the main P30 list are five sub lists; these are the 500m Sub-Pedwar, 500m Double Sub-Pedwar, 400m Sub-Pedwar, 390m Sub-Pedwar and 390m Double Sub-Pedwar category’s, with their criteria detailed in the respective Change Registers that have been created and which are linked in their above titles, with the Introduction to this list being linked in the above title.

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








Mapping Mountains - Hill Reclassifications - Y Pedwarau

Pt. 459.9m (SN 768 794) – 400m Sub-Pedwar reinstated (67th reclassification)


There has been a hill reinstated to the listing of Y Pedwarau due to 1m DSM LIDAR analysis conducted by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reinstated to the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar status is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

The hill was listed as a 400m Sub-Pedwar with c 20m of drop based on the 459m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 439m based on interpolation of bwlch contouring between 430m – 440m.

The hill was then deleted from the ranks of 400m Sub-Pedwarau based on DTM LIDAR analysis which gave a summit height of 459.84m at SN 76846 79457 and a bwlch height of 439.86m at SN 77051 79549, with these values giving this hill 19.98m of drop.

The hill is situated in the Elenydd range with its Cardinal Hill being Draws Drum (SN 790 811and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the small community of Pontarfynach (Devil’s Bridge) to the south-west and Ponterwyd to the north-west.

The hill is a part of designated open access land and can be approached directly from the A 4120 and B 4343 roads which are to the west of the summit, public footpaths also give access to the open access land and originate towards the north-west and the west respectively, otherwise if wanting to visit the hill a longer route can be devised that takes in a number of adjacent hills.

The hill is being listed under the point (Pt. 459.9m) notation as an appropriate name for it either from local or historical research is not known by the authors, and its reinstatement as a 400m Sub-Pedwar is due to 1m DSM LIDAR analysis conducted by Aled Willams.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

The 1m DSM LIDAR analysis gives the hill the following details:


Pt. 459.9m

Summit Height:  459.92m

Summit Grid Reference:  SN 76846 79456

Bwlch Height:  439.92m

Bwlch Grid Reference:  SN 77052 79547

Drop:  20.00m


1m DSM LIDAR image of Pt. 459.9m


Therefore, the 459.9m 1m DSM LIDAR analysis for the summit position at SN 76846 79456 and the 439.9m 1m DSM LIDAR analysis for the bwlch position at SN 77052 79547 gives this hill 20.0m of drop which is sufficient for it to be reinstated as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Draws Drum

Summit Height:  459.9m (LIDAR)

Name:  Pt. 459.9m

OS 1:50,000 map:  135, 147

Summit Grid Reference:  SN 76846 79456

Drop:  20.0m (LIDAR)


For the additions, reclassifications and deletions to the Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the 1st edition of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (July 2018)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Mynydd Ty’n y Fach (SH 687 097) – 400m Sub-Pedwar deletion (66th reclassification)

Survey post for Mynydd Ty'n y Fach


There has been a deletion to the listing of Y Pedwarau due to LIDAR analysis conducted by Myrddyn Phillips and subsequently confirmed via a survey with the Trimble GeoXH 6000.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being deleted from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar status is all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.

Prior to LIDAR analysis this hill was listed with c 20m of drop based on the 409m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated bwlch height of c 389m based on interpolation of bwlch contouring between 380m – 390m.

The name of the hill is Mynydd Ty’n y Fach and it is situated in the Cadair Idris range of hills and is placed in the Region of North Wales (Region A, Sub-Region A3).  The hill is positioned between the stream valleys of the Afon Cadair to the west and the Afon Dysynni to the south-east, and has the small community of Abergynolwyn to its south south-west.

Mynydd Ty'n y Fach (SH 687 097)

As the summit of the hill is a part of designated open access land permission to visit does not need to be sought, and there are a number of public footpaths accessing the open access land from a variety of directions.

The deletion of Mynydd Ty’n y Fach from 4000m Sub-Pedwar status is due to LIDAR analysis conducted by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 


1m DTM LIDAR analysis gives the hill the following details:


Mynydd Ty’n y Fach

Summit Height:  408.0m (LIDAR)

Summit Grid Reference:  SH 68788 09702

Bwlch Height:  389.5m (LIDAR) 

Bwlch Grid Reference:  SH 69048 09685

Drop:  18.6m


LIDAR image of Mynydd Ty'n y Fach

Therefore, the 408.0m LIDAR analysis produced for the summit position at SH 68788 09702 and the 389.45m LIDAR analysis produced for the bwlch position at SH 69048 09685 gives this hill 18.6m of drop, and as the drop is below 20m it is insufficient for this hill to retain its 400m Sub-Pedwar status, with the details from the Trimble GeoXH 6000 survey being 408.4m (converted to OSGM15) summit at SH 68787 09703 and 389.5m (converted to OSGM15) bwlch at SH 69047 09685, giving this hill 18.9m of drop.


The full details for the hill are:

Cardinal Hill:  Cadair Idris 

Name:  Mynydd Ty’n y Fach

Summit Height:  408.4m (converted to OSGM15)

OS 1:50,000 map:  124

Summit Grid Reference:  SH 68787 09703

Drop:  18.9m (converted to OSGM15)


The Trimble GeoXH 6000 gathering data at the summit of Mynydd Ty'n y Fach

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (May 2018)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Allt y Genlli (SN 985 950) – 390m Sub-Pedwar reinstated to 390m Double Sub-Pedwar (65th reclassification)


There has been a reclassification to the listing of Y Pedwarau due to a survey with a Leica GS15 conducted by John Barnard, Chris Crocker and Graham Jackson.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from a 390m Sub-Pedwar to a 390m Double Sub-Pedwar.  The criteria for 390m Sub-Pedwar status being all Welsh hills at or above 390m and below 400m in height that have 30m minimum drop, whilst the criteria for 390m Double Sub-Pedwar status being  all Welsh hills at or above 390m and below 400m in height with 20m or more and below 30m of drop.

The name of the hill is Allt y Genlli and prior to the survey with the Leica GS15 the hill was listed with 73.2m of drop, based on a 398.9m summit and 325.7m bwlch, with these values obtained from LIDAR analysis and the resulting Hill Reclassifications post appearing on Mapping Mountains on the 24.05.17.  Its adjacent peak of Mynydd Garth Pwt was also analysed using LIDAR resulting in a 30.5m drop, based on a 397.8m summit and 367.3m bwlch.  As LIDAR gave Allt y Genlli as higher their respective bwlch positions and heights were swapped resulting in Allt y Genlli being reclassified to a 390m Sub-Pedwar The survey with the Leica GS15 has now reversed this classification to pre LIDAR analysis.

The hill is a part of the Pumlumon range with its Cardinal Hill being Bryn Amlwg (SN 921 973) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is situated to the south of the A 470 and is positioned between the small communities of Carno to its west north-west and Clatter to its east. 

Although the upper section of the hill is a part of designated open access land it is also immersed in conifer plantation.  The summit of the hill is encircled by a forest track and for those determined souls who wish to visit; an approach from the north using this track may be the best option.

The survey with the Leica GS15 resulted in a summit height of 395.76m and a bwlch height of 367.05m, with these values giving this hill 28.7m of drop, which is insufficient for its retention as a 390m Sub-Pedwar.

  
The full details for the two hills are:


Cardinal Hill:  Bryn Amlwg

Name:  Allt y Genlli

Summit Height:  395.8m

OS 1:50,000 map:  136

Summit Grid Reference:  SN 98508 95041
  
Drop:  28.7m



Cardinal Hill:  Bryn Amlwg

Name:  Mynydd Garth Pwt

Summit Height:  397.8m

OS 1:50,000 map:  136

Summit Grid Reference:  SN 98154 94173 

Drop:  72.1m


For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:











Our thanks to John Barnard, Chris Crocker and Graham Jackson for bringing the survey result of this hill to our attention

Myrddyn Phillips and Aled Williams (May 2018)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Garth Fawr (SO 085 059) – Pedwar addition (64th reclassification)


There has been an addition to the listing of Y Pedwarau due to detail on OS Maps, which is the recent replacement for OS Get-a-map.  The Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at and above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

The name of the hill is Garth Fawr and prior to analysis of contours on the OS Maps website this hill was not listed as it is a relatively recent man-made construction and is the result of waste spoil from the Ffos-y-fran opencast mine that is now considered solid and stable, therefore it does not possess any separate ring contours for the area of its summit on either the Ordnance Survey 1:50,000 Landranger or the 1:25,000 Explorer map.

Garth Fawr is situated in the Y Cymoedd – dwyreiniol range of hills and is placed in the Region of South Wales (Region C, Sub-Region C2).  The hill is positioned between the towns of Merthyr Tudful (Merthyr Tydfil) to its north-west and Rhymni (Rhymney) to its north-east and has the A 465 Heads of the Valleys Road to its north and the A 4060 road to its west.

As the summit of this hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a minor road to the south would give access to the hill.

Garth Fawr had little natural prominence and is a southerly spur of Twyn y Waun, but due to mining activity its height has increased with the 5m contour intervals on OS Maps giving it three separate uppermost 410m ring contours and a bwlch height of c 376m based on contouring between 375m – 380m, whilst LIDAR analysis conducted by Aled Williams gives the summit height as 388.0m at SO 08521 05968 and the height of the bwlch as 374.8m at SO 08618 06004.  It is apparent that the mine spoil was deposited after the measurement of LIDAR data was taken.  Therefore, as the hill is considered solid and stable these values are sufficient for it to be listed as a Pedwar with c 39m of drop.


The full details for the hill are:

Cardinal Hill:  Twyn y Waun

Summit Height:  c 414m

Name:  Garth Fawr

OS 1:50,000 map:  160

Summit Grid Reference:  SO 085 059

Drop:  c 39m


For the additions, deletions and reclassifications to the Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:









Garth Fawr (SO 085 059) is now classified as a Pedwar.  Photo: Rob Woodall

Myrddyn Phillips and Aled Williams (January 2018)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Twyn y Waun (SO 085 065) – Pedwar addition (63rd reclassification)

Survey post for Twyn y Waun

Significant Height Revisions post for Twyn y Waun


There has been an addition to the listing of Y Pedwarau due to a survey with the Trimble GeoXH 6000 that was instigated by an on-site visit by Rob Woodall and an article written by Aled Williams in 2015 entitled ‘Artificial Pedwar Hills.’  The Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at and above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

The name of the hill is Twyn y Waun and prior to the Trimble GeoXH 6000 survey this hill was not listed as it is a relatively recent man-made construction and is the result of waste spoil that is now considered solid and stable from the Ffos-y-fran opencast mine, therefore it does not possess separate ring contours on either the Ordnance Survey 1:50,000 Landranger or the 1:25,000 Explorer map.

Twyn y Waun is situated in the Y Cymoedd – dwyreiniol range of hills and is placed in the Region of South Wales (Region C, Sub-Region C2).  The hill is positioned between the towns of Merthyr Tudful (Merthyr Tydfil) to its west and Rhymni (Rhymney) to its east and has the A 465 Heads of the Valleys Road to its north-west.

As the summit of this hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so a minor road to the north north-east of the hill gives access to a public footpath and a track that heads toward the critical bwlch of this hill.

The survey with the Trimble GeoXH 6000 resulted in a summit height of 460.5m (converted to OSGM15) and a bwlch height of 419.5m (converted to OSGM15), with these values giving this hill 41.0m of drop, and as this artificial hill is considered to be solid and stable in character these values are sufficient for it to be classified as a Pedwar.


The full details for the hill are:

Cardinal Hill:  Twyn y Waun 

Summit Height:  460.5m

Name:  Twyn y Waun

OS 1:50,000 map:  160

Summit Grid Reference:  SO 08549 06591

Drop:  41.0m


For the additions, deletions and reclassifications to the Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Twyn y Waun (SO 085 065) is now included as a Pedwar

For details on the survey of Twyn y Waun

Myrddyn Phillips and Aled Williams (January 2018)







Mapping Mountains - Hill Reclassifications - Y Pedwarau

Twyn y Waun (artificial summit at SO 082 070 and natural summit at SO 084 073) – Pedwar reclassified to Dual Summit Pedwar (62nd reclassification)

Survey post for Twyn y Waun

Significant Height Revisions post for Twyn y Waun


There has been a reclassification to the listing of Y Pedwarau due to a survey with the Trimble GeoXH 6000 that was instigated by an on-site visit by Rob Woodall and an article written by Aled Williams in 2015 and entitled ‘Artificial Pedwar Hills.’  The Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at and above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, however this hill has not been reclassified from one of these categories to another, as a new classification of Dual Summit has been created to accommodate the details relating to this hill.

Dual Summit hills:

A hill classified as a Dual Summit is defined as one which has an extant natural summit coupled with that of a higher artificial summit, with the latter that can be described as stable in character.  In the main, these recent man-made constructions are the result of quarrying activities producing spoil tips.  These recent man-made constructions are treated differently to ancient man-made constructions such as hill forts and tumuli, as if the latter are deemed stable and of an earthen character their age dictates that they can be viewed as being permanent in nature and are now effectively a part of the hill.  For those bagging Dual Summit hills, a visit to either the natural high point or the elevated man-made high point is sufficient to claim an ascent of the hill.

The name of the hill is Twyn y Waun and prior to the Trimble GeoXH 6000 survey this hill was listed with an estimated c 451m summit height based on a 450m uppermost contour on the Ordnance Survey 1:50,000 map and the Interactive Coverage Map hosted on the Geograph website and a drop of c 63m which has now been re-evaluated.

Twyn y Waun is situated in the Y Cymoedd – dwyreiniol range of hills and is listed as a Cardinal Hill, and is placed in the Region of South Wales (Region C, Sub-Region C2).  The hill is positioned between the towns of Merthyr Tudful (Merthyr Tydfil) to its west and Rhymni (Rhymney) to its east and has the A 465 Heads of the Valleys Road to its north-west.

Twyn y Waun is now listed as a Dual Summit hill and its natural summit is a part of designated open access land and can be approached from the convenience of a minor road to its east, whilst as its man-made summit is a part of a working mine permission to visit should be sought, however the artificial summit is on the border of designated open access land shown on the Ordnance Survey 1:25,000 Explorer map, and for those wishing to visit an ascent of this artificial summit from the natural summit is  an easy extension of the short walk from the minor road to the east.


The full details for the hill are:

Cardinal Hill:  Twyn y Waun 

Summit Height:  476.0m (artificial Dual Summit) c 451m (natural Dual Summit)

Name:  Twyn y Waun

OS 1:50,000 map:  160

Summit Grid Reference:  SO 08209 07041 (artificial Dual Summit) SO 08457 07348 (natural Dual Summit)

Drop:  c 96m (artificial Dual Summit) c 71m (natural Dual Summit)


For the additions, deletions and reclassifications to the Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:

The Dual Summit of Twyn y Waun with the pastoral natural summit in the foreground and the man-made summit in the background










Myrddyn Phillips and Aled Williams (January 2018)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Craig y Garreg Lwyd (SH 730 427) – 400m Sub-Pedwar reinstated to Pedwar (61st reclassification)

Survey post for Craig y Garreg Lwyd

Significant Height Revisions post for Craig y Garreg Lwyd


There has been a reclassification to the listing of Y Pedwarau due to a survey with a Leica GS15 conducted by John Barnard and Graham Jackson.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height that have 20m and more and below 30m of drop.

The name of the hill is Craig y Garreg Lwyd and prior to the survey with the Leica GS15 the hill was listed with 29.9m of drop based on a 473.4m (converted to OSGM15) summit and 443.5m (converted to OSGM15) bwlch height ascertained from a survey with the Trimble GeoXH 6000 and which resulted in this hill’s reclassification from a Pedwar to a 400m Sub-Pedwar.

Craig y Garreg Lwyd is situated in the Arenig range of hills with its Cardinal Hill being Graig Goch (SH 751 447) and is placed in the Region of North Wales (Region A, Sub-Region A3).  The hill is positioned overlooking the B 4391 which is to its south, with the communities of Llan Ffestiniog to the west south-west and Blaenau Ffestiniog to the north-west of the hill.

The hill is a part of designated open access land and can be accessed either from its south-west, south or south-east where tracks make their way toward the lower part of the hill.  However, the hills surrounding Craig y Garreg Lwyd are recommended to visit and so combining it with its near neighbours is worthwhile.

The survey with the Leica GS15 resulted in a summit height of 473.8m and a bwlch height of 443.6m, with these values giving this hill 30.2m of drop, which is sufficient for it to be re-instated as a Pedwar.


The full details for the hill are:

Cardinal Hill:  Graig Goch 

Summit Height:  473.8m (converted to OSGM15)

Name:  Craig y Garreg Lwyd

OS 1:50,000 map:  124

Summit Grid Reference:  SH 73047 42746

Drop:  30.2m (converted to OSGM15)


The total for Y Pedwarau is now 443 hills with eleven additions, and fifteen reclassifications to either 400m Sub-Pedwar status or 390m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 217 with 27 hills being added and 23 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Craig y Garreg Lwyd (SH 730 427) is now re-instated as a Pedwar

Myrddyn Phillips and Aled Williams (October 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Bwlch y Cefn Bank (SO 123 608) – Pedwar reclassified to 390m Sub-Pedwar (60th reclassification)

Survey post for Bwlch y Cefn Bank 


There has been a reclassification to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams and subsequently confirmed via a survey with the Trimble GeoXH 6000.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified to the 390m Sub-Pedwar category.  The criteria for 390m Sub-Pedwar qualification is all Welsh hills at or above 390m and below 400m in height that have a minimum 30m of drop.

Prior to analysis of LIDAR data this hill was listed with c 52m of drop based on the 400m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and an estimated bwlch height of c 348m based on interpolation of bwlch contouring between 340m – 350m.

The name of the hill is Bwlch y Cefn Bank and it is situated in the Elfael range of hills with its Cardinal Hill being Gilwern Hill (SO 098 582) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1).  The hill is positioned above the A 44 road which is to its east and to its north, and the Afon Ieithon (River Ithon) which is to its north-west, and with the small community of Llandegley to the north north-east of the hill.

As the summit of the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so the land to the north-east and the south-west of the hill is a part of designated open access land, and a public footpath crosses between each just to the south-east of this hill’s summit.

The reclassification of Bwlch y Cefn Bank to 390m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Bwlch y Cefn Bank

Summit Height:  399.0m

Summit Grid Reference:  SO 12367 60871

Bwlch Height:  347.1m

Bwlch Grid Reference:  SO 12752 60893

Drop:  51.9m


Therefore, the 399.0m LIDAR data produced for the summit position at SO 12367 60871 and the 347.1m LIDAR data produced for the bwlch position at SO 12752 60893 gives this hill 51.9m of drop, and as the summit height is below 400m it is insufficient for this hill to retain its Pedwar status, with the details from the Trimble GeoXH 6000 survey being 399.9m (converted to OSGM15) summit at SO 12369 60880 and 347.2m (converted to OSGM15) bwlch at SO 12752 60893, giving this hill a summit height below 400m.


The full details for the hill are:

Cardinal Hill:  Gilwern Hill 

Summit Height:  399.9m (converted to OSGM15)

Name:  Bwlch y Cefn Bank

OS 1:50,000 map:  148

Summit Grid Reference:  SO 12369 60880

Drop:  52.7m (converted to OSGM15)


The total for Y Pedwarau is now 442 hills with ten additions, and fifteen reclassifications to either 400m Sub-Pedwar status or 390m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau remains at 218 with 27 hills being added and 22 hills being taken out of this category since publication of the list by Europeaklist in May 2013, whilst the 390m Sub-Pedwar total increases by one to 38 hills.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:









Bwlch y Cefn Bank (SO 123 608) is now included in the 390m Sub-Pedwar listing of hills

For details on the survey that confirmed this hill's 390m Sub-Pedwar status


Myrddyn Phillips and Aled Williams (September 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Waun Sidan (SO 250 726) – 400m Sub-Pedwar reclassified to Pedwar (59th reclassification)

Survey post for Waun Sidan

Significant Name Changes post for Waun Sidan


There has been a reclassification to the listing of Y Pedwarau due to LIDAR analysis conducted by Aled Williams and subsequently confirmed via a survey with the Trimble GeoXH 6000.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to LIDAR analysis this hill was listed with 29m of drop based on a basic levelling survey (BLS) conducted by Myrddyn Phillips on the 05.10.03, with the summit height listed as 406m which is taken from the spot height that appears on the Ordnance Survey 1:25,000 Explorer map, based on the map summit height and the BLS these values place the height of the bwlch at 377m.

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

The name of the hill is Waun Sidan and it is situated in the Maelienydd range of hills with its Cardinal Hill being Bwlch Bank (SO 242 720) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1).  The hill is positioned above the B 4355 road and the River Teme which are to its north-east, and the A 488 road which is to its south, with the town of Trefyclo (Knighton) towards the east.

Waun Sidan (SO 250 726)

As the summit of the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so the long distance footpath of Glyndŵr’s Way passes just to the south of the summit.

The reclassification of Waun Sidan to Pedwar status is due to LIDAR analysis conducted by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Waun Sidan

Summit Height:  407.7m

Summit Grid Reference:  SO 25021 72649

Bwlch Height:  376.3m

Bwlch Grid Reference:  SO 24638 72691

Drop:  31.4m


Therefore, the 407.7m LIDAR data produced for the summit position at SO 25021 72649 and the 376.3m LIDAR data produced for the bwlch position at SO 24638 72691 gives this hill 31.4m of drop which is sufficient for it to be classified as a Pedwar, with the details from the Trimble GeoXH 6000 survey being 407.8m (converted to OSGM15) summit height at SO 25022 72649 and 376.3m (converted to OSGM15) bwlch height at SO 24638 72691, giving this hill 31.5m of drop.



The full details for the hill are:

Cardinal Hill:  Bwlch Bank 

Summit Height:  407.8m (converted to OSGM15)

Name:  Waun Sidan

OS 1:50,000 map:  137, 148

Summit Grid Reference:  SO 25022 72649

Drop:  31.5m (converted to OSGM15)


The total for Y Pedwarau is now 443 hills with ten additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 218 with 27 hills being added and 22 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (September 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Yr Allt (SO 074 755) – 400m Sub-Pedwar deletion (58th reclassification)


There has been a deletion from the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being deleted from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data this hill was listed with 25m of drop based on the 436m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 411m bwlch spot height that appears on the Ordnance Survey enlarged mapping hosted on the Geograph website.

The name of the hill is Yr Allt and it is situated in the Hirddywel range of hills with its Cardinal Hill being Pt. 508m (SO 041 783) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1).  The hill is positioned above the stream valleys of the Crychell Brook to its west and the Afon Ieithon (River Ithon) to its east, with the small community of Llanbadarn Fynydd towards the north-east and Llananno towards the east south-east.

The summit of the hill is a part of designated open access land with the long distance footpath of Glyndŵr’s Way just to the east of the summit.  There are public footpaths that lead to the open access land from the north-west and south-east of the hill.

The deletion of Yr Allt from 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Yr Allt

Summit Height:  437.6m

Summit Grid Reference:  SO 07419 75572

Bwlch Height:  418.5m

Bwlch Grid Reference:  SO 07410 75952

Drop:  19.1m


Therefore, the 437.6m LIDAR data produced for the summit position at SO 07419 75572 and the 418.5m LIDAR data produced for the bwlch position at SO 07410 75952 gives this hill 19.1m of drop which is insufficient for its retention as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Pt. 508m (SO 041 783)  

Summit Height:  437.6m (LIDAR data)

Name:  Yr Allt

OS 1:50,000 map:  136, 147

Summit Grid Reference:  SO 07419 75572

Drop:  19.1m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 219 with 27 hills being added and 21 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (September 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Cefn Cynllaith (SN 892 515) – 400m Sub-Pedwar addition (57th reclassification)


There has been an addition to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being added to the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was listed with 16m of drop based on the 404m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 388m bwlch spot height that appears on the Ordnance Survey enlarged mapping hosted on the Geograph website.

The name of the hill is Cefn Cynllaith and it is situated in the Elenydd range with its Cardinal Hill being Pen y Garn Goch (SN 884 502) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is positioned above the stream valleys of the Nant yr Annell to the north and the Nant Einon to the south, with the small community of Beulah towards its east.

As the summit of the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so the nearest approach via a public footpath is from the south and over the Nant Einon to a track below the summit.  Alternatively a longer approach from the east via another public footpath leads to the same track just south of the summit.

The addition of Cefn Cynllaith to 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Cefn Cynllaith

Summit Height:  405.0m

Summit Grid Reference:  SN 89292 51575

Bwlch Height:  383.9m

Bwlch Grid Reference:  SN 89176 51655

Drop:  21.1m


Therefore, the 405.0m LIDAR data produced for the summit position at SN 89292 51575 and the 383.9m LIDAR data produced for the bwlch position at SN 89176 51655 gives this hill 21.1m of drop which is sufficient for its inclusion as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Pen y Garn Goch

Summit Height:  405.0m (LIDAR data)

Name:  Cefn Cynllaith

OS 1:50,000 map:  147

Summit Grid Reference:  SN 89292 51575

Drop:  21.1m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 220 with 27 hills being added and 20 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:











Myrddyn Phillips and Aled Williams (August 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Pt. 442.9m (SN 945 643) – 400m Sub-Pedwar addition (56th reclassification)


There has been an addition to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being included in the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was not classified as its uppermost 430m ring contour that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and bwlch contouring between 420m – 430m did not even warrant it an estimated P14m.

The hill is situated in the Elenydd range with its Cardinal Hill being Gorllwyn (SN 917 590), and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned above the small community of the Elan Village to its north-west and Llanwrthwl to its east south-east.

The summit of the hill is a part of designated open access land and has public footpaths approaching it from the north, south-west, south and south-east, all of which bisect with the open access land.

The name of the hill is being listed under the point (Pt. 442.9m) notation as the authors do not know an appropriate name for it either from local enquiry or from historical research, and its addition to 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Pt. 442.9m

Summit Height:  442.9m 

Summit Grid Reference:  SN 94528 64354

Bwlch Height:  422.3m

Bwlch Grid Reference:  SN 94272 64477

Drop:  20.6m


Therefore, the 442.9m LIDAR data produced for the summit position at SN 94528 64354 and the 422.3m LIDAR data produced for the bwlch position at SN 94272 64477 gives this hill 20.6m of drop which is sufficient for its inclusion as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Gorllwyn

Summit Height:  442.9m (LIDAR data)

Name:  Pt. 442.9

OS 1:50,000 map:  147

Summit Grid Reference:  SN 94528 64354

Drop:  20.6m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 219 with 26 hills being added and 20 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (August 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Pt. 389.3m (SN 952 552) – 390m Sub-Pedwar deletion (55th reclassification)


There has been a deletion to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being deleted from the 390m Sub-Pedwar category.  The criteria for 390m Sub-Pedwar status being all Welsh hills at or above 390m and below 400m in height that have a minimum 30m of drop.

Prior to analysis of LIDAR data the hill was listed with 76m of drop based on the 390m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 314m bwlch spot height that appears on the Ordnance Survey enlarged mapping hosted on the Geograph website.

The hill is situated in the Elenydd range with its Cardinal Hill being Gorllwyn (SN 917 590and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), the hill is positioned between the small communities of Llanafan Fawr to the east north-east and Glandulas towards the south.

As the hill is not a part of designated open access land permission to visit should be sought, if permission is granted there are public footpaths that approach the hill from the north, west and south.

The hill is being listed by the point (Pt. 389.3m) notation as the authors do not know an appropriate name for it either from local enquiry or from historical research, and its deletion from 390m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Pt. 389.3m

Summit Height:  389.3m

Summit Grid Reference:  SN 95203 55201

Bwlch Height:  314.4m

Bwlch Grid Reference:  SN 95556 55887

Drop:  74.9m


Therefore, the 389.3m LIDAR data produced for the summit position at SN 95203 55201 and the 314.4m LIDAR data produced for the bwlch position at SN 95556 55887 gives this hill 74.9m of drop and with its summit height being below 390m it is insufficient for its continued inclusion as a 390m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Gorllwyn

Summit Height:  389.3m (LIDAR data)

Name:  Pt. 389.3m

OS 1:50,000 map:  147

Summit Grid Reference:  SN 95203 55201

Drop:  74.9m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The total for the 390m Sub-Pedwarau decreases by one to 37 hills and the total for the 390m Double Sub-Pedwarau remains at 26 hills.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (July 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Disgwylfa (SN 982 663) – 400m Sub-Pedwar deletion (54th reclassification)


There has been a deletion to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being deleted from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was listed with 20m of drop based on the 477m summit spot height and the 457m bwlch spot height that appear on the Ordnance Survey enlarged mapping hosted on the Geograph website.

The hill is situated in the Hirddywel range with its Cardinal Hill being Gwastedyn Hill (SN 986 661and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1), and is positioned above the A 470 road which is to its north-west and has the town of Rhaeadr Gwy (Rhayader) to the north north-west.

As the summit of the hill is not a part of designated open access land permission should be sought to visit, however common sense should prevail as the summit is a local landmark and as the name of the hill implies it is a look out position, and as open access land is close to the high point to its immediate south, a visit to its summit should not course any dispute.

The name of the hill is Disgwylfa, although the area of the summit is also named as a part of Gwastedyn Hill, and its deletion from 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Disgwylfa

Summit Height:  475.5m

Summit Grid Reference:  SN 98210 66310

Bwlch Height:  456.1m

Bwlch Grid Reference:  SN 98422 66294

Drop:  19.4m


Therefore, the 475.5m LIDAR data produced for the summit position at SN 98210 66310 and the 456.1m LIDAR data produced for the bwlch position at SN 98422 66294 gives this hill 19.4m of drop which is insufficient for its continued inclusion as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Gwastedyn Hill

Summit Height:  475.5m (LIDAR data)

Name:  Disgwylfa

OS 1:50,000 map:  136, 147

Summit Grid Reference:  SN 98210 66310

Drop:  19.4m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 218 with 25 hills being added and 20 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Disgwylfa (SN 982 663) is now deleted from the 400m Sub-Pedwar category

Myrddyn Phillips and Aled Williams (July 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Cyrnau Mawr (SN 751 750) – 390m Double Sub-Pedwar addition (53rd reclassification)

Survey post for Cyrnau Mawr


There has been an addition to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams and subsequently confirmed via a survey with the Trimble GeoXH 6000.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being included in the 390m Double Sub-Pedwar category.  The criteria for 390m Double Sub-Pedwar status being  all Welsh hills at or above 390m and below 400m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was not classified but it was catalogued with c 16m of drop based on an estimated c 390m summit height and an estimated c 374m bwlch height, the latter height based on bwlch contouring between 370m – 380m.

The hill is a part of the Elenydd range with its Cardinal Hill being Pen y Garn (SN 798 771) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is situated with the B 4574 to its north and the B 4343 to its west and is positioned between the small communities of Pontarfynach (Devil’s Bridge) to its north-west and Cwmystwyth to its east south-east.  

For those wishing to visit the summit the whole upper section of the hill is a part of designated open access land, and this has immediate access from the B 4343 to the west or from a public footpath from the same road that intersects with the open access lane.

The name of the hill is Cyrnau Mawr and its addition to 390m Double Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Cyrnau Mawr

Summit Height:  391.4m

Summit Grid Reference:  SN 75155 75007

Bwlch Height:  369.8m

Bwlch Grid Reference:  SN 75343 74906

Drop:  21.6m


Therefore, the 391.4m LIDAR data produced for the summit position at SN 75155 75007 and the 369.8m LIDAR data produced for the bwlch position at SN 75343 74906 gives this hill 21.6m of drop which is sufficient for its inclusion as a 390m Double Sub-Pedwar, with the details from the Trimble GeoXH survey being 391.4m (converted to OSGM15) summit at SN 75154 75006 and 369.8m (converted to OSGM15) bwlch at SN 75342 24906, giving this hill 21.6m of drop. 


The full details for the hill are:

Cardinal Hill:  Pen y Garn

Summit Height:  391.4m (converted to OSGM15 Trimble, and LIDAR data)

Name:  Cyrnau Mawr

OS 1:50,000 map:  135, 147

Summit Grid Reference:  SN 75154 75006  

Drop:  21.6m (converted to OSGM15 Trimble, and LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The total for the 390m Sub-Pedwarau remains at 38 hills, whilst the total for the 390m Double Sub-Pedwarau increases by one to 26 hills.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:









Cyrnau Mawr (SN 751 750) confirmed as a 390m Double Sub-Pedwar







Mapping Mountains - Hill Reclassifications - Y Pedwarau

Pt. 459.9m (SN 768 794) – 400m Sub-Pedwar deletion (52nd reclassification)


THIS HILL HAS SUBSEQUENTLY BEEN RE-INSTATED TO 400m SUB-PEDWAR STATUS

There has been a deletion to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being deleted from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was listed with c 20m of drop based on the 459m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 439m based on interpolation of bwlch contouring between 430m – 440m.

The hill is situated in the Elenydd range with its Cardinal Hill being Draws Drum (SN 790 811and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the small community of Pontarfynach (Devil’s Bridge) to the south-west and Ponterwyd to the north-west.

The hill is a part of designated open access land and can be accessed directly from the A 4120 and B 4343 roads which are to the west of the summit, public footpaths also give access to the open access land and originate towards the north-west and the west respectively, otherwise if wanting to visit the hill a longer route can be devised that takes in a number of adjacent hills.

The hill is being listed under the point (Pt. 459.9m) notation as an appropriate name for it either from local or historical research is not known by the authors, and its deletion from 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Pt. 459.9m

Summit Height:  459.9m (converted to OSGM15)

Summit Grid Reference:  SN 76846 79457

Bwlch Height:  439.9m (converted to OSGM15)

Bwlch Grid Reference:  SN 77051 79549

Drop:  19.98m


Therefore, the 459.9m LIDAR data produced for the summit position at SN 76846 79457 and the 439.9m LIDAR data produced for the bwlch position at SN 77051 79549 gives this hill 19.98m of drop which is insufficient for its continued inclusion as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Draws Drum

Summit Height:  459.9m (converted to OSGM15, LIDAR data)

Name:  Pt. 459.9m

OS 1:50,000 map:  135, 147

Summit Grid Reference:  SN 76846 79457

Drop:  19.98m (converted to OSGM15, LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 219 with 25 hills being added and 19 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (June 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Coed yr Artsh (SN 764 760) – 400m Sub-Pedwar addition (51st reclassification)


There has been an addition to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being added to the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was not classified, but it was catalogued with c 18m of drop based on the 444m summit spot height on the Ordnance Survey enlarged mapping hosted on the Geograph website and an estimated bwlch height of c 426m based on interpolation of bwlch contouring between 420m – 430m.

The hill is situated in the Elenydd range with its Cardinal Hill being Pen y Garn (SN 798 771and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the small community of Pontarfynach (Devil’s Bridge) to the west north-west and Cwmystwyth to the south-east.

The hill is not a part of designated open access land and therefore permission to visit should be sought, however it is a part of a large conifer forest that has many designated forest walks in it, and according to Ordnance Survey maps a path leaves one of these walks and heads through to trees to the summit, if this path exists on the ground those wishing to visit may have a relatively easy route to the hill’s high point.

The name of the hill is Coed yr Artsh and its addition to 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Coed yr Artsh

Summit Height:  443.5m

Summit Grid Reference:  SN 76472 76079

Bwlch Height:  422.0m

Bwlch Grid Reference:  SN 76593 76052

Drop:  21.5m


Therefore, the 443.5m LIDAR data produced for the summit position at SN 76472 76079 and the 422.0m LIDAR data produced for the bwlch position at SN 76593 76052 gives this hill 21.5m of drop which is sufficient for its inclusion as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Pen y Garn

Summit Height:  443.5m (LIDAR data)

Name:  Coed yr Artsh

OS 1:50,000 map:  135, 147

Summit Grid Reference:  SN 76472 76079

Drop:  21.5m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 220 with 25 hills being added and 18 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (June 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Bryn yr Ysbyty (SN 985 995) – 400m Sub-Pedwar addition (50th reclassification)


There has been an addition to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being added to the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was originally catalogued with c 20m of drop which would have qualified it for 400m Sub-Pedwar status, this was re-evaluated and in doing so contours were misinterpolated, resulting in the hill being catalogued with c 14m of drop and therefore it was not considered for inclusion in the 400m Sub-Pedwar category.

The hill is situated in the Carnedd Wen range with its Cardinal Hill being Garreg Hir (SN 998 979) and is placed in the Region of North Wales (Region A, Sub-Region A4), and is positioned with the small community of Carno to the south-west and Clatter to the south south-east.

The hill is a part of designated open access land and although it is immersed in conifer plantation, a track enters the forest from east of the summit and gives access to a forest ride which ploughs its way through the conifers and comes relatively close to the high point, and dependent upon tree proximity any onward progress from here may prove problematic.

The name of the hill is Bryn yr Ysbyty and its addition to 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Bryn yr Ysbyty

Summit Height:  435.2m

Summit Grid Reference:  SN 98523 99527

Bwlch Height:  413.3m

Bwlch Grid Reference:  SN 99024 99915

Drop:  21.9m


Therefore, the 435.2m LIDAR data produced for the summit position at SN 98523 99527 and the 413.3m LIDAR data produced for the bwlch position at SN 99024 99915 gives this hill 21.9m of drop which is sufficient for its inclusion as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Garreg Hir

Summit Height:  435.2m (LIDAR data)

Name:  Bryn yr Ysbyty

OS 1:50,000 map:  136

Summit Grid Reference:  SN 98523 99527

Drop:  21.9m (LIDAR data)


The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 219 with 24 hills being added and 18 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (June 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Fuches (SN 866 836) – Pedwar reclassified to 400m Sub-Pedwar (49th reclassification)


There has been a reclassification to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from a Pedwar to a 400m Sub-Pedwar.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was listed with c 76m of drop based on an estimated summit height of c 453m and an estimated bwlch height of c 377m with the latter based on interpolation of bwlch contouring between 370m – 380m.  The reclassification of this hill is dependent upon the analysis of LIDAR data for it, and its adjacent east south-easterly hill of Allt y Derw (SN 873 834), with the height of the highest hill swapping, with this affecting the position of the critical bwlch of both hills and the status of Fuches.

The hill is situated in the Pumlumon range with its Cardinal Hill being Pumlumon Fawr (SN 789 869) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the small community of Llangurig to the south-east of the hill.

The hill is a part of designated open access land and although it is immersed in conifer plantation, a forest ride crosses the summit ridge in a north-east to south-west direction which gives relatively easy access to its high point.

The name of the hill is Fuches and its reclassification from Pedwar to a 400m Sub-Pedwar is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Fuches

Summit Height:  446.7m

Summit Grid Reference:  SN 86610 83643

Bwlch Height:  419.2m

Bwlch Grid Reference:  SN 87000 83839

Drop:  27.5m


Therefore, the 446.7m LIDAR data produced for the summit position at SN 86610 83643 and the 419.2m LIDAR data produced for the bwlch position at SN 87000 83839 gives this hill 27.5m of drop which is insufficient for its retention as a Pedwar.


The full details for the hill are:

Cardinal Hill:  Pumlumon Fawr

Summit Height:  446.7m (LIDAR data)

Name:  Fuches

OS 1:50,000 map:  135, 136

Summit Grid Reference:  SN 86610 83643

Drop:  27.5m (LIDAR data)


This reclassification now brings the total for Y Pedwarau to 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 218 with 23 hills being added and 18 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:









The forested summit of Fuches (SN 866 836)

Myrddyn Phillips and Aled Williams (June 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Bryn Crugog (SN 941 923) – 400m Sub-Pedwar reclassified to Pedwar (48th reclassification)


There has been a reclassification to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from a 400m Sub-Pedwar to a Pedwar.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was listed with c 20m of drop based on the 447m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated bwlch height of c 427m based on interpolation of bwlch contouring between 420m – 430m.  The reclassification of this hill is dependent upon the analysis of LIDAR data for it, and its adjacent north-westerly hill of Esgair Hir (SN 937 925), with the height of the highest hill swapping, with this affecting the position of the critical bwlch of both hills and their status.  The Hill Reclassifications post for Esgair Hir will appear separately.

The hill is situated in the Pumlumon range with its Cardinal Hill being Bryn Amlwg (SN 921 973) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the small community of Llawr-y-glyn to the south-west.

As the summit is not a part of designated open access land permission to visit should be sought, however there is a public footpath that approaches from the east and heads just south of the high point of the hill.

The name of the hill is Bryn Crugog and its reclassification from 400m Sub-Pedwar to Pedwar is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Bryn Crugog

Summit Height:  446.7m

Summit Grid Reference:  SN 94130 92357

Bwlch Height:  394.0m

Bwlch Grid Reference:  SN 93183 93473

Drop:  52.7m


Therefore, the 446.7m LIDAR data produced for the summit position at SN 94130 92357 and the 394.0m LIDAR data produced for the bwlch position at SN 93183 93473 gives this hill 52.7m of drop which is sufficient for its reclassification to a Pedwar.


The full details for the hill are:

Cardinal Hill:  Bryn Amlwg

Summit Height:  446.7m (LIDAR data)

Name:  Bryn Crugog

OS 1:50,000 map:  136

Summit Grid Reference:  SN 94130 92357

Drop:  52.7m (LIDAR data)


This reclassification now brings the total for Y Pedwarau to 443 hills with nine additions, and thirteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 217 with 22 hills being added and 18 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (June 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Esgair Hir (SN 937 925) – Pedwar reclassified to 400m Sub-Pedwar (47th reclassification)


There has been a reclassification to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from a Pedwar to a 400m Sub-Pedwar.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was listed with c 51m of drop based on the 448m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 397m based on interpolation of bwlch contouring between 390m – 400m.  The reclassification of this hill is dependent upon the analysis of LIDAR data for it, and its adjacent south-easterly hill of Bryn Crugog (SN 941 923), with the height of the highest hill swapping, with this affecting the critical bwlch of both hills and their status.  The Hill Reclassifications post for Bryn Crugog will appear separately.

The hill is situated in the Pumlumon range with its Cardinal Hill being Bryn Amlwg (SN 921 973) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the small community of Llawr-y-glyn towards its south-west.

As the summit is not a part of designated open access land permission to visit should be sought, however there are a number of public footpaths that approach the summit from the south, north and the east, all meeting just west of the high point of the hill.

The name of the hill is Esgair Hir and its reclassification from Pedwar to 400m Sub-Pedwar is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Esgair Hir

Summit Height:  446.5m

Summit Grid Reference:  SN 93723 92558

Bwlch Height:  423.7m

Bwlch Grid Reference:  SN 94106 92683

Drop:  22.8m


Therefore, the 446.5m LIDAR data produced for the summit position at SN 93723 92558 and the 423.7m LIDAR data produced for the bwlch position at SN 94106 92683 gives this hill 22.8m of drop which is insufficient for its continued inclusion as a Pedwar.


The full details for the hill are:

Cardinal Hill:  Bryn Amlwg

Summit Height:  446.5m (LIDAR data)

Name:  Esgair Hir

OS 1:50,000 map:  136

Summit Grid Reference:  SN 93723 92558

Drop:  22.8m (LIDAR data)


This reclassification now brings the total for Y Pedwarau to 442 hills with eight additions, and thirteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 218 with 22 hills being added and 17 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (June 2017)






Mapping Mountains - Hill Reclassifications - Y Pedwarau

Allt y Genlli (SN 985 950) – 390m Double Sub-Pedwar reclassified to 390m Sub-Pedwar (46th reclassification)


THIS HILL HAS SUBSEQUENTLY BEEN RE-INSTATED TO 390m DOUBLE SUB-PEDWAR STATUS

The following details have been superseded by a survey conducted by John Barnard, Chris Crocker and Graham Jackson using a Leica GS15 with the result that this hill has been re-instated to 390 Double Sub-Pedwar status with 28.7m of drop.

Below is the Hill Reclassifications post prior to the Leica GS15 survey:


There has been a reclassification to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being reclassified from a 390m Double Sub-Pedwar to a 390m Sub-Pedwar.  The criteria for 390m Double Sub-Pedwar status being  all Welsh hills at or above 390m and below 400m in height with 20m or more and below 30m of drop, with the criteria for 390m Sub-Pedwar status being all Welsh hills at or above 390m and below 400m in height that have a minimum 30m of drop.

Prior to analysis of LIDAR data the hill was listed as a 390m Double Sub-Pedwar and its reclassification is dependent upon the LIDAR data analysis of it, and its southerly adjacent hill of Mynydd Garth Pwt, because of this the previously listed details of both hills based on map data are given below:



Allt y Genlli (previously listed as 390m Double Sub-Pedwar)

Summit Height:  394m (OS 1:25,000 Explorer map)

Summit Grid Reference:  SN 985 950

Bwlch Height:  367m (OS enlarged mapping hosted on the Geograph website)

Bwlch Grid Reference:  SN 983 944

Drop:  27m




Mynydd Garth Pwt (listed as 390m Sub-Pedwar)

Summit Height:  397m (OS 1:50,000 Landranger and 1:25,000 Explorer maps)

Summit Grid Reference:  SN 981 941

Bwlch Height:  c 325m

Bwlch Grid Reference:  SN 973 941

Drop:  c 72m



The hill is a part of the Pumlumon range with its Cardinal Hill being Bryn Amlwg (SN 921 973) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is situated to the south of the A 470 and is positioned between the small communities of Carno to its west north-west and Clatter to its east. 

Although the whole upper part of the hill is a part of designated open access land it is also immersed in conifer plantation.  The summit of the hill is encircled by a forest track and for those determined souls who wish to visit; an approach from the north using this track may be the best option, however only an on-site visit could determine how problematic an ascent could be.

The name of the hill is Allt y Genlli and its reclassification from 390m Double Sub-Pedwar to 390m Sub-Pedwar status is dependent upon its adjacent southerly hill of Mynydd Garth Pwt and the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives these two hills the following details:


Allt y Genlli

Summit Height:  398.9m

Summit Grid Reference:  SN 98508 95042

Bwlch Height:  325.7m

Bwlch Grid Reference:  SN 97387 94159

Drop:  73.2m




Mynydd Garth Pwt

Summit Height:  397.8m

Summit Grid Reference:  SN 98154 94173

Bwlch Height:  367.3m

Bwlch Grid Reference:  SN 98385 94438

Drop:  30.5m


Therefore, as the 398.9m LIDAR data produced for the summit position of Allt y Genlli at SN 98508 95042 is higher than the 397.8m LIDAR data produced for the summit position of Mynydd Garth Pwt at SN 98154 94173, the lower bwlch is the critical bwlch for the higher of the two hills, therefore the listed bwlch position of each hill is swapped.


The full details for the two hills are:


Cardinal Hill:  Bryn Amlwg

Summit Height:  398.9m (LIDAR data)

Name:  Allt y Genlli

OS 1:50,000 map:  136

Summit Grid Reference:  SN 98508 95042
  
Drop:  73.2m (LIDAR data)




Cardinal Hill:  Bryn Amlwg

Summit Height:  397.8m (LIDAR data)

Name:  Mynydd Garth Pwt

OS 1:50,000 map:  136

Summit Grid Reference:  SN 98154 94173 
Drop:  30.5m (LIDAR data)



The total for Y Pedwarau remains at 443 hills with eight additions, and twelve reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The total for the 390m Double Sub-Pedwarau decreases by one to 25 hills and the total for the 390m Sub-Pedwarau increases by one to 38 hills.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (May 2017)


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