Mapping Mountains – Significant Name Changes – 100m Twmpau and Y Trechol – The Dominant Hills of Wales

Cae Glas (SS 712 946)

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height and its location, and the drop of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Cae Glas (SS 712 946)

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

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 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.

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 western part of South Wales (Region C, Sub-Region C2), and it is positioned with the Crymlyn Bog to its west, the Tennant Canal and the A483 road to its south and the B4290 and M4 roads to its east, and has the town of Castell-nedd (Neath) towards its north-east.

The hill originally appeared in the 100m P30 list on Geoff Crowder’s v-g.me website under a partly invented and transposed name of Pen Pant-y-sais, with an accompanying note stating; Name from valley to the South-East.

 

Pen Pant-y-Sais

106m

SS713946

170

165

Name from valley to the South-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 what I presumed to be a valley and add the word Pen 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 288 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 Cae Glas in the apportionments, with the details on the Tithe map appearing in the parish of Cadoxton Juxta Neath in the county named as Glamorgan.

Extract from the apportionments

Therefore, the name this hill is now listed by in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales is Cae Glas, and this name was derived from the Tithe map.

The full details for the hill are:

Group:  Fforest Fawr

Name:  Cae Glas

Previously Listed Name:  Pen Pant-y-sais

  

OS 1:50,000 map:  170

Summit Height:  107.1m (LIDAR)

Summit Grid Reference:  SS 71271 94675 (LIDAR)

Bwlch Height:  38.2m (LIDAR, natural bwlch)

Bwlch Grid Reference:  SS 71439 96229 (LIDAR, natural bwlch) 

Drop:  68.9m (LIDAR)

Dominance:  64.34% (LIDAR)

Myrddyn Phillips (April 2019)