Mapping Mountains – Significant Name Changes – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

Coed Darcy (SS 711 955)

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau and which was listed in the Y Trechol – The Dominant Hills of Wales, with the summit height, its location, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR summit image of Coed Darcy (SS 711 955)

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

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m 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.

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The hill is adjoined to the Fforest Fawr group of hills, which are situated in the northern part of South Wales (Region C, Sub-Region C2), and it is positioned with the B4290 and M4 roads to its east, and has the town of Castell-neth (Neath) towards the north-east.

The hill originally appeared in the 30-99m P30 list on Geoff Crowder’s v-g.me website under a partly transposed and invented name of Crymlyn Oil Refinery, with an accompanying note stating; Name from bog to the West and oil refinery at the summit. 

Crymlyn Oil Refinery

80c

SS711955

170

165

Name from bog to the West and oil refinery at the summit

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 bog and what I presumed to be the name of an oil refinery that was positioned on the summit of the hill.  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 from 1998

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

Since publication of these P30 lists on Geoff Crowder’s v-g.me website the oil refinery has been dismantled and a regeneration project is underway with 4,000 new homes planned.  The area of regeneration also takes in that of this hill and it is named Coed Darcy.

Extract from the website giving details of the Coed Darcy regeneration project

Therefore the name this hill is now listed by in the 30-99m Twmpau and was listed by (before its deletion due to the hill having less than 30m of drop) in the Y Trechol – The Dominant Hills of Wales is Coed Darcy, and this was derived from the name of the regeneration project taking place on the hill.

The full details for the hill are:

Group:  Fforest Fawr

Name:  Coed Darcy

Previously Listed Name:  Crymlyn Oil Refinery 

OS 1:50,000 map:  170

Summit Height:  80.4m (LIDAR)

Summit Grid Reference:  SS 71147 95565 (LIDAR)

Bwlch Height:  53.0m (LIDAR)

Bwlch Grid Reference:  SS 71330 95324 (LIDAR) 

Drop:  27.4m (LIDAR)

Dominance:  N/A, insufficient drop (LIDAR)

Myrddyn Phillips (May 2019)