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

Carreglefain (SH 324 410) - Lesser Dominant reclassified to Dominant

There has been a reclassification to the listing of Y Trechol – The Dominant Hills of Wales due to a survey with the Trimble GeoXH 6000.  This has resulted in the hill being reclassified from a Lesser Welsh Dominant to a Dominant hill.  With the criteria for inclusion to this list being those Welsh P30 hills whose prominence equal or exceed half that of their absolute height.

The details relating to this hill’s inclusion as a Dominant hill are retrospective as it appeared in the Pen Llŷn group of hills when published on the Mapping Mountains site on the 11^th February 2016.

Prior to this hill’s inclusion as a Dominant hill it was listed as a Lesser Welsh Dominant hill with 48.66% Dominance based on its 261m summit spot height that appears on Ordnance Survey 1:25,000 Explorer maps and a c 127m drop based on bwlch contouring between 130m – 140m with an estimated bwlch height of c 134m.

The hill is listed in the Pen Llŷn group and is placed in the Region of North Wales (Region A, Sub-Region A1) with its Cardinal Hill being Garn Ganol (SH 278 351), and it is situated between the small communities of Nefyn towards the west and Llithfaen to the north-east.

If wanting to visit the hill it can be accessed from a number of directions via public footpaths that lead to open access land that takes in the supper section of the hill.

The name of the hill is Carreglefain and the Trimble survey that resulted in its reclassification was conducted by Myrddyn Phillips on the 24^th November 2014 resulting in a 260.7m (converted to OSGM15) summit height and a 130.1m (converted to OSGM15) bwlch height, with these values giving this hill 130.6m of drop and 50.08% of Dominance.

The full details for the hill are:

Group:  Pen Llŷn

Name:  Carreglefain

Dominance:  50.08%

OS 1:50,000 map:  123

Summit Grid Reference:  SH 32421 41054

Summit Height:  260.7m (converted to OSGM15)

Drop Summit to Bwlch:  130.6m

Drop Bwlch to ODN:  130.1m (converted to OSGM15) 

Carreglefain (SH 324 410) now reclassified from a Lesser Welsh Dominant to a Dominant hill

For details on the survey that reclassified this hill to Dominant status

Myrddyn Phillips (March 2017)