Mapping Mountains – Significant Name Changes – The Welsh P15s

Cae Mawr (SN 462 175) 

There has been a Significant Name Change to a hill that is listed in The Welsh P15s, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cae Mawr (SN 462 175)

This hill is also listed as the natural summit for a Dual Summit 100m Twmpau and a Dual Summit Lesser Dominant hill along with the man-made summit of Safle Claddu Nant y Caws (SN 468174 and SN 469 174).  However, this hill also qualifies as a Welsh P15, without the distinction of it being a Dual Summit hill, with its bwlch listed adjoined to the higher man-made summit.

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

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is adjoined to the Mynydd Sylen group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with the A48 road to its north and a minor road to its south-west, and has the town of Caerfyrddin (Carmarthen) towards the north-west.

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill appeared under the transposed name of Llwynmelyn, with an accompanying note stating; Name from buildings to the West.

Llwynmelyn

155m

SN464176

159

178

Clem/Yeaman. Trig pillar. Name from buildings to the 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, with little consideration for the meaning of the name and where it was appropriately applied to.  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 use it for that 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

When the listing that became known as The Welsh P15s was being compiled, this hill was included as a separate entry in the main list under the point (Pt. 155m) notation with an estimated c 17m of drop, based on the 155m summit spot height adjoined to a triangulation pillar positioned at SN 46405 17608 that appears on the Ordnance Survey 1:50,000 Landranger andf 1:25,000 Explorer map, and an estimated c 138m bwlch height, based on interpolation of 5m contouring between 135m – 140m.  With the higher man-made summit of Safle Claddu Nant y Caws forming a part of the Dual Summit P30 entry in the 100m Twmpau. 

Extract from the Tithe 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 apportionments

The enclosed land where the summit of this hill is situated is given the number 886 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 Mawr in the apportionments, with the details on the Tithe map appearing in the parish named as Llangynnwr and in the county named as Carmarthen.

Therefore, the name this hill is now listed by in The Welsh P15s is Cae Mawr and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Mynydd Sylen 

Name:  Cae Mawr

Previously Listed Name:  Llwynmelyn (original 100m P30 list) Pt. 155m (original P15 list when summits were separated) 

OS 1:50,000 map:  159

Summit Height:  155.1m (LIDAR)                                                           

Summit Grid Reference:  SN 46268 17566 (LIDAR)                                                  

Bwlch Height:  139.3m (LIDAR) 

Bwlch Grid Reference:  SN 46733 17459 (LIDAR) 

Drop:  15.8m (LIDAR) 

 

Myrddyn Phillips (May 2025)