Mapping Mountains – Significant Name Changes – 100m Twmpau

Crug Cwm (SN 612 257) 

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail produced by Joe Nuttall in his surface analysis programme, with subsequent LIDAR analysis conducted by the DoBIH team and independently by Myrddyn Phillips. 

LIDAR image of Crug Cwm (SN 612 257)

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

100m Twmpau – Welsh hills at or above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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. 

100m Twmpau by Myrddyn Phillips

The hill is adjoined to the Mynydd Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the A40 road farther to its south and the B4302 road farther to its east, and has the town of Llandeilo towards the south south-east.

The hill appeared in the original Welsh 100m P30 list on Geoff Crowder’s v-g.me website, under the invented and transposed name of Twyn y Crugcwm, with an accompanying note stating; Name from buildings to the East.

Twyn y Crugcwm

190c

SN613259

146

186

Name from buildings to the East.

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 farm and add the words Twyn 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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 3474 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as a part of Crug Cwm farm in the apportionments, with the details on the Tithe map appearing in the parish of Llandeilo Fawr and in the county named as Carmarthen. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 100m Twmpau is Crug Cwm, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Mynydd Mallaen

Name:  Crug Cwm

Previously Listed Name:  Twyn y Crugcwm   

OS 1:50,000 map:  146

Summit Height:  192.8m (LIDAR) 

Summit Grid Reference:  SN 61260 25753 (LIDAR) 

Bwlch Height:  159.0m (LIDAR) 

Bwlch Grid Reference:  SN 63103 27207 (LIDAR) 

Drop:  33.8m (LIDAR) 

 

Myrddyn Phillips (February 2024)