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

Ponciau Tre Wilmot (SH 227 816) 

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and by LIDAR analysis conducted by Myrddyn Phillips. 

Ponciau Tre Wilmot (SH 227 816)

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. 

The 30-99m Twmpau by Myrddyn Phillips

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, and which is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Ynys Môn group of hills which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned on Ynys Gybi (Holyhead Island) to the west of Ynys Môn, and is encircled by minor roads with the A55 farther to its east, and has the town of Caergybi (Holyhead) towards the east. 

The hill appeared in the original 30-99m Welsh P30list on Geoff Crowder’s v-g.me website under the transposed name of Tre-wilmot, with an accompanying note stating; Name from buildings to the North-West.

Tre-wilmot

77m

SH228817

114

262

Name from buildings to the North-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.  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 an old 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

This was one of a number of hills visited during the day and I was eventually directed to Wyn Roberts who lives at Glan Gors Goch Uchaf.  As I explained my interest in the hill and its name, Wyn invited me in and offered me a cup of tea, explaining as he did so that the name of the series of little tops that take in this hill is Ponciau Tre Wilmot. 

Therefore, the name this hill is now listed by in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales is Ponciau Tre Wilmot and this was derived from local enquiry.

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Ponciau Tre Wilmot

Previously Listed Name:  Tre-wilmot 

OS 1:50,000 map:  114

Summit Height:  76.6m (LIDAR)

Summit Grid Reference:  SH 22772 81657 (LIDAR)

Bwlch Height:  c 38m (interpolation)

Bwlch Grid Reference:  SH 21685 81120 (interpolation) 

Drop:  c 39m (LIDAR summit and interpolated bwlch)

Dominance:  50.41% (LIDAR summit and interpolated bwlch)

 

Myrddyn Phillips (April 2021)