Mapping Mountains – Significant Name Changes – Y Trichant – The 300m Hills of Wales

 

Cefn Gwyn (SO 028 995) 

There has been a Significant Name Change to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cefn Gwyn (SO 028 995)

The criteria for the list that this name change applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Carnedd Wen group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with minor roads to its north, west and east, and the A470 road to its south-west, and has the village of Caersŵs towards the south.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed under the point (Pt. 382m) notation with 21m of drop, based on the 382m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and the 361m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of maps made available online.  Some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website.  Whilst others were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites, and it is the Ordnance Survey series of Six-Inch maps that give the name of Cefn Gwyn taking in the summit of this hill at contrast to its current position on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey series of Six-Inch maps

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Cefn Gwyn, and the name placement was confirmed by the Ordnance Survey series of Six-Inch maps. 

 

The full details for the hill are: 

Group:  Carnedd Wen 

Name:  Cefn Gwyn 

Previously Listed Name:  Pt. 382m 

OS 1:50,000 map:  136

Summit Height:  382.7m (LIDAR)                                                           

Summit Grid Reference:  SO 02813 99573 (LIDAR) 

Bwlch Height:  362.0m (LIDAR) 

Bwlch Grid Reference:  SO 02633 99303 (LIDAR) 

Drop:  20.6m (LIDAR) 

 

Myrddyn Phillips (October 2022)