Mapping Mountains – Hill Reclassifications – Welsh Highlands – Uchafion Cymru

 

Pt. 906.2m (SH 619 551) – Welsh Highland Sub reinstatement 

There has been a reinstatement to the listing of the Welsh Highlands – Uchafion Cymru, with the summit height, bwlch height and their locations, the drop and status of the hill derived from a Trimble GeoXH 6000 survey conducted by Aled Williams. 

Pt. 906.2m (SH 619 551).  Photo: Aled Williams

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

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

Welsh Highlands - Uchafion Cymru by Aled Williams and Myrddyn Phillips

The hill is being listed by the point (Pt. 906.2m) notation and it is adjoined to the Yr Wyddfa group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A4086 road to its north-east, the A4085 road to its west and the A498 road to its south-east, and has the village of Nant Peris towards the north north-west. 

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

When the initial P10 sub list was completed in June 2020 this hill was listed with 10.4m of drop, based on a basic levelling survey conducted by Myrddyn Phillips on the 20.09.98, and listed with a 906m summit height an 896m bwlch height, with an accompanying note stating that analysis of numerical data on various scales of Ordnance Survey maps give this hill 9m of drop.  Therefore, it was included as a Welsh Highland Sub when the drop value of the subs was agreed upon and revised in July 2020. 

LIDAR image of Pt. 906.2m (SH 619 551)

The hill was subsequently analysed via LIDAR by Aled Williams, resulting in a 906.2m summit height and an 896.4m bwlch height, with these values giving this hill 9.8m of drop, which was insufficient for it to be classified as a Welsh Highland Sub.  However, with the drop value relatively close to the qualifying criterion of 10m this hill was prioritised for a survey with the Trimble GeoXH 6000. 

The Trimble GeoXH 6000 gathering data at the summit of Pt. 906.2m (SH 619 551).  Photo: Aled Williams

Therefore, the reinstatement of this hill to Welsh Highland Sub status is due to a Trimble GeoXH 6000 survey, resulting in a 906.2m summit height and an 896.1m bwlch height, with these values giving this hill 10.1m of drop, which is sufficient for it to be classified as a Welsh Highland Sub. 

 

The full details for the hill are: 

Group:  Yr Wyddfa

Name:  Pt. 906.2m          

OS 1:50,000 map:  115

Summit Height:  906.2m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SH 61983 55146 (Trimble GeoXH 6000)

Bwlch Height:  896.1m (converted to OSGM15, Trimble GeoXH 6000)

Bwlch Grid Reference:  SH 61885 55154 (Trimble GeoXH 6000)   

Drop:  10.1m (Trimble GeoXH 6000) 

 

For the additions, deletions and reclassifications to the Welsh Highlands – Uchafion Cymru reported on Mapping Mountains please consult the following Change Registers:

 

Welsh Highland P15s

 

Welsh Highland Subs

 

Aled Williams and Myrddyn Phillips (January 2025)