Mapping Mountains – Significant Name Changes – 200m Twmpau

Llwynderw Hill (SJ 196 036) 

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 derived from LIDAR analysis and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

LIDAR image of Llwynderw Hill (SH 196 036)

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 is positioned with minor roads to its north, west and south and the A483 road to its south-east, and has the town of Y Trallwng (Welshpool) towards the north-east. 

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 Pen y Belan, with an accompanying note stating; Name from surrounding district.

 

Pen y Belan

238m

SJ196036

136

216

Name from surrounding district

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 the district where the hill is situated and add the words Pen 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

When I first visited this hill in June 2011 I called at Mount Farm (SJ 190 040) and met Peter Holloway.  Peter is local to the area and has farmed from Mount Farm all of his life.  I asked about the names of a number of local hills and for this hill he told me that he knows it as Llwynderw Hill. 

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

 

The full details for the hill are:

Group:  Carnedd Wen

Name:  Llwynderw Hill

Previously Listed Name:  Pen y Belan   

OS 1:50,000 map:  136

Summit Height:  237.9m (converted to OSGM15, Trimble GeoXH 6000) 

Summit Grid Reference:  SJ 19600 03662 (Trimble GeoXH 6000) 

Bwlch Height:  159.7m (LIDAR) 

Bwlch Grid Reference:  SJ 18827 03989 (LIDAR) 

Drop:  78.3m (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

Myrddyn Phillips (June 2021)