Mapping Mountains – Hill Reclassifications – Y Trechol – The Dominant Hills of Wales

Foel Fawr (SM 705 225) - Lesser Dominant addition

There has been a new entry in to the ranks of Y Trechol – The Dominant Hills of Wales due to a survey with the Trimble GeoXH 6000 and which has resulted in the hill being listed in The Lesser Dominant Hills of Wales list.  The hill is in the group known as the Pembrokeshire Islands and is situated on the southern part of Ynys Dewi, which is also commonly known as Ramsey.  This island is situated to the west of St David’s in the south-west of Wales.

The Trimble GeoXH 6000 survey that resulted in this hill’s reclassification was conducted on the 15^th May 2016 on a beautiful afternoon in still and sunny conditions.

As the hill is situated on an island the only way to approach is via boat and the only company with permission to land on Ynys Dewi is Thousand Island Adventures (tel: 01437-721721).  The hill can be easily accessed from where the boat docks as a gravelled track leads up to The Farmhouse from where a good path heads toward the southern part of the island.

The name of the hill is Foel Fawr and until the survey with the Trimble GeoXH 6000 the hill was listed with c 29m of drop, based on the 72m summit spot height on current Ordnance Survey maps, and an estimated bwlch height of c 43m based on bwlch contouring between 40m – 45m, with these values giving the hill c 29m of drop which is insufficient for qualification to the Y Trechol – The Dominant Hills of Wales list.

The survey with the Trimble GeoXH 6000 resulted in a 72.0m (71.954m, converted to OSGM15) summit height and a 41.9m (41.899m, converted to OSGM15)) bwlch height, with these values giving the hill 30.1m of drop and a Dominance of 41.77% which is sufficient for it to qualify as a Lesser Welsh Dominant hill.

The full details for the hill are:

Group:  Pembrokeshire Islands

Name:  Foel Fawr

Dominance:  41.77%

OS 1:50,000 map:  157

Summit Grid Reference:  SM 70542 22567

Summit Height:  72.0m (converted to OSGM15)

Drop Summit to Bwlch:  30.1m

Drop Bwlch to ODN:  41.9m (converted to OSGM15)  

Foel Fawr (SM 705 225) now classified as a Lesser Welsh Dominant

For details on the survey that resulted in this hill being classified as a Lesser Welsh Dominant

Myrddyn Phillips (May 2016)