Mapping Mountains – Significant Name Changes – 200m Twmpau

 

Cefn Dinas (SO 129 964) 

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

LIDAR image of Cefn Dinas (SO 129 964)

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

200m Twmpau - Welsh hills at or above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 200m Twmpau by Myrddyn Phillips

The hill is adjoined to the Carnedd Wen group of hills which are situated in the south-eastern part of North Wales (Region A, Sub-Region A4), and it has minor roads to its north, south and east and the B4389 road to its west, and has the village of Betws Cedewain towards the west north-west. 

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was listed under the invented and transposed name of Bryn y Cefn-dinas, with an accompanying note stating; Name from coppice to the North-West.

Bryn y Cefn-dinas

223m

SO130964

136

215

Name from coppice to the North-West

 

During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose the name of a near wood and add the words Bryn y to it.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found. 

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

This was one of a number of hills visited during the hill in the company of Alex Cameron, and when descending the hill I flagged down a vehicle heading toward us on a track.  The driver was the local gamekeeper, who we had briefly talked to whilst driving up the narrow road leading to the start of the track heading up the hill.  During our conversation he confirmed that he had heard the name of Cefn Dinas used for this hill. 

Therefore, the name this hill is now listed by in the 200m Twmpau is Cefn Dinas, and this was derived from local enquiry. 

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Cefn Dinas

Previously Listed Name:  Bryn y Cefn-dinas   

OS 1:50,000 map:  136

Summit Height:  221.3m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SO 12992 96463 (Trimble GeoXH 6000) 

Bwlch Height:  176.6m (LIDAR) 

Bwlch Grid Reference:  SO 13331 96892 (LIDAR) 

Drop:  44.7m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (April 2021)