Mapping Mountains – Significant Name Changes – 500m Twmpau

Banc Nant Rhys (SN 822 802) 

There has been a Significant Name Change to a hill that is listed in the 500m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted for the Welsh Highlands –Uchafion Cymru list authored by Aled Williams and Myrddyn Phillips. 

LIDAR image of Banc Nant Rhys (SN 822 802)

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

500m Twmpau – Welsh hills at or above 500m and below 600m in height with 30m minimum drop, with an accompanying sub category entitled the 500m Sub-Twmpau consisting of all Welsh hills at or above 500m and below 600m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips and is available in its entirety on Mapping Mountains in Google Doc format, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

The 500m Twmpau by Myrddyn Phillips

The hill is adjoined to the Y Garn group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B1), and it is positioned with the A44 road to its north, the A4120 road to its west and a minor road to its south, and has the village of Ponterwyd towards the west.

When the listing that later became known as the 500m Twmpau was first compiled this hill appeared under the name of Bryn Llychese, which is a prominent name that appears to the north of this hill on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

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 a prominent name that appeared on contemporary Ordnance Survey maps.  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.

Since the original compilation of this list there have been a number of maps made available online.  Some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website.  Whilst others were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites, and it is the series of Ordnance Survey Six-Inch maps that form the basis of the change in the listed name of this hill. 

Extract from the Ordnance Survey series of Six-Inch maps

The Ordnance Survey series of Six-Inch maps formed the base map Ordnance Survey used for many decades leading to the production of the 1:10,000 Series of maps, both have now been superseded by the digitised Master Map.  The series of Six-Inch maps are excellent for name placement and especially so compared to the contemporary Ordnance Survey 1:25,000 Explorer map, and it is the series of Six-Inch maps that give the name of Banc Nant Rhys applicable to this hill.

Therefore, the name this hill is now listed by in the 500m Twmpau is Banc Nant Rhys and the placement of this name being applicable to this hill was confirmed by the Ordnance Survey series of Six-Inch maps. 

 

The full details for the hill are: 

Group:  Y Garn 

Name:  Banc Nant Rhys 

Previously Listed Name:  Bryn Llychese 

OS 1:50,000 map:  135, 136 

Summit Height:  566.5m (LIDAR) 

Summit Grid Reference:  SN 82222 80222 (LIDAR) 

Bwlch Height:  538.0m (LIDAR) 

Bwlch Grid Reference:  SN 81007 80687 & SN 81009 80686 (LIDAR) 

Drop:  28.5m (LIDAR) 

 

Myrddyn Phillips (April 2023)