Mapping Mountains – Hill Reclassifications – Y Pedwarau

Moel yr Acre (SJ 169 526) – 400m Sub-Pedwar deletion

There has been a deletion to the listing of Y Pedwarau due to analysis of data on the OS Maps website, which is the recent replacement for OS Get-a-map.

Moel yr Acre (SJ 169 526)

The criteria for the list that this deletion applies to are:

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height with 30m minimum drop, 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 being all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

The name of the hill is Moel yr Acre, and it is adjoined to the Bryniau Clwyd group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the A525 road to its south, the B5429 road to its north-west and the B5431 road its north-east, and has the town of Rhuthun (Ruthin) towards the north-west.

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

Prior to analysis of data on OS Maps this hill was listed with c 20m of drop based on the 411.3m summit height ascertained from a Leica GS15 survey conducted by John Barnard and Myrddyn Phillips and an estimated bwlch height of c 391m based on interpolation of bwlch contouring between 390m – 395m on the Ordnance Survey 1:25,000 Explorer map.

Extract from the OS Maps website

The deletion of Moel yr Acre from 400m Sub-Pedwar status is due to the analysis of data on the OS Maps website and a re-assessment of bwlch contouring on the Ordnance Survey 1:25,000 Explorer map.  Therefore with a 411.3m summit height from the Leica GS15 survey and an estimated bwlch height of c 392m, based on bwlch contouring on OS Maps between 390m – 395m, this hill is now listed with c 19m of drop, which is insufficient for it to be classified as a 400m Sub-Pedwar. 

The full details for the hill are:

Group:  Bryniau Clwyd

 

Name:  Moel yr Acre

OS 1:50,000 map:  116

Summit Height:  411.3m (converted to OSGM15)

Summit Grid Reference:  SJ 16955 52668

Bwlch Height:  c 392m

Bwlch Grid Reference:  SJ 16994 53034 (interpolation)

Drop:  c 19m

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:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

Myrddyn Phillips and Aled Williams (October 2019)

Mapping Mountains – Hill Reclassifications – Y Pedwarau

Fuches (SN 866 836) – 400m Sub-Pedwar reinstated to Pedwar

There has been a reclassification to the listing of Y Pedwarau due to a survey with the Trimble GeoXH 6000 which took place on the 03.06.18.  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 status is all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.

The name of the hill is Fuches and prior to the Trimble GeoXH 6000 survey it was listed with 27.5m of drop, based on LIDAR analysis giving a 446.7m summit and 419.2m bwlch height.  This hill’s adjacent peak of Allt y Derw (SN 873 834) was also analysed using LIDAR resulting in a 449.9m summit height.  As LIDAR gave Allt y Derw as higher the respective bwlch positions and heights of these two hills were swapped resulting in Fuches being reclassified to a 400m Sub-Pedwar.  This hill was then re-analysed via LIDAR by Chris Crocker resulting in a different conclusion, therefore the DSM LIDAR model was re-analysed resulting in the conclusion that Fuches was a marginal Pedwar and the Trimble GeoXH 6000 survey was done to confirm this, resulting in the classification of this hill reversing to pre LIDAR analysis, with the caveat that Allt y Derw is being listed as the higher of the two hills.

The hill is a part of 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).  The hill is situated between the stream valleys of the Afon Hafren (River Severn) to the north-east and the Afon Gwy (River Wye) to the south, and has the small community of Llangurig towards the south-east. 

Fuches (SN 866 836)

Although the hill is a part of designated open access land it is also immersed in conifer plantation.  However, the summit of the hill is easily reached via a wide path now used by trail riders that follows the summit ridge in a north-east to south-west direction, and this can be accessed from a forest track to the north-east of the summit.

The survey with the Trimble GeoXH 6000 resulted in a summit height of 449.3m for Fuches and 450.0m for Allt y Derw, confirming Allt y Derw as higher and therefore the connecting bwlch between each hill is the critical bwlch for the lower hill; Fuches, and this was surveyed as being 419.1m in height, with these values giving Fuches 30.2m of drop, which is sufficient for its reinstatement to Pedwar status.

 

The full details for the two hills are:

Cardinal Hill:  Pumlumon Fawr

Name:  Fuches

OS 1:50,000 map:  135, 136

Summit Height:  449.3m (converted to OSGM15)

Summit Grid Reference:  SN 86623 83656

Bwlch Height:  419.1m (converted to OSGM15)

Bwlch Grid Reference:  SN 86997 83837  

  

Drop:  30.2m

Cardinal Hill:  Pumlumon Fawr

Name:  Allt y Derw

OS 1:50,000 map:  135, 136

Summit Height:  450.0m (converted to OSGM15)

Summit Grid Reference:  SN 87314 83429

Bwlch Height:  375.6m (LIDAR)

Bwlch Grid Reference:  SN 86411 83855 (LIDAR)

Drop:  74.4m (Trimble summit and LIDAR bwlch)

 

The Trimble GeoXH 6000 set-up position at the summit of Fuches

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:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

Our thanks to Chris Crocker for suggesting that the data produced by LIDAR be re-evaluated for this hill

For details relating to the survey of Fuches

LIDAR and Trimble GeoXH 6000 analysis for Fuches (SN 866 836)

Myrddyn Phillips and Aled Williams (September 2018)

Mapping Mountains – Hill Reclassifications – Y Pedwarau

Pt. 486m (SH 774 462) – 400m Sub-Pedwar addition

There has been an addition to the listing of Y Pedwarau due to analysis of data on the OS Maps website, which is the recent replacement for OS Get-a-map.  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 co-authored by Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Llyn Conwy from Pt. 486m (SH 774 462)

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 status are all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.

Prior to analysis of data on OS Maps this hill was listed with c 19m of drop based on the 486m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 467m based on interpolation of bwlch contouring between 460m – 470m.

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

The hill is being listed by the point (Pt. 486m) notation until an appropriate name for it can be confirmed, and it is situated in the Arenig 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 Machno to the north-west and the Afon Conwy to the south-east, with Llyn Conwy to its immediate east, and has the small community of Penmachno to its north north-east.

As the summit of the hill is a part of designated open access land it can be approached from a number of directions, with the minor road to its west giving the easiest and most convenient starting point.

The addition of Pt. 486m to 400m Sub-Pedwar status is due to the analysis of data on the OS Maps website.  This mapping gives contour intervals at 5m which has enabled the height of the bwlch to be narrowed down when compared to the 10m contour intervals given on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps.  Therefore with a 486m summit spot height on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 466m (based on latest mapping), based on bwlch contouring on OS Maps between 465m – 470m, this hill is now listed with c 20m of drop, which is sufficient for it to be classified as a 400m Sub-Pedwar. 

Extract from OS Maps

The full details for the hill are:

Cardinal Hill:  Graig Goch 

Name:  Pt. 486m

Summit Height:  486m

OS 1:50,000 map:  124

Summit Grid Reference:  SH 774 462

Drop:  c 20m

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:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

Myrddyn Phillips and Aled Williams (July 2018)

Mapping Mountains – Hill Reclassifications – Y Pedwarau

Twyn y Waun (SO 085 065) – Pedwar addition

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:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

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

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.

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.

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) 450.6m (converted to OSGM15, Trimble GeoXH 6000, natural Dual Summit)

Name:  Twyn y Waun

OS 1:50,000 map:  160

Summit Grid Reference:  SO 08209 07041 (artificial Dual Summit) SO 08442 07378 (LIDAR, natural Dual Summit)

Drop:  96.0m (Trimble GeoXH 6000 summit and LIDAR bwlch, artificial Dual Summit) 70.7m (Trimble GeoXH 6000 summit and LIDAR bwlch, 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

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

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

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:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

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

Myrddyn Phillips and Aled Williams (October 2017)