Mapping Mountains – Significant Name Changes – 30-99m Twmpau

 

Parc Penrhyn (SH 601 720) 

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau, 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 Parc Penrhyn (SH 601 720)

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

30-99m Twmpau – Welsh hills at or above 30m and below 100m in height that have 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.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

30-99m Twmpau by Myrddyn Phillips

The hill is adjoined to the Glyder Fawr group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A5 road to its west and the A55 road to its south-east, and has the city of Bangor towards the west.

When the original 30-99m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed under the transposed name of Penrhyn Castle, which is a prominent name that appears adjacent to the summit of this hill on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, with the land where the castle is situated named as Penrhyn Park on the 1:25,000 Explorer map.  With its numerical details given as an estimated c 19m of drop, based on an estimated c 53m summit height and an estimated c 34m bwlch height, with both heights based on interpolation of 10m contouring. 

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

The intricacies of language and prioritising one in favour of another for listing a hill is fraught with complication, with originating Cymraeg names being anglicised and also originating English names being cymricised, examples such as these are more common in border country and especially so for anglicised forms.  There is no steadfast rule that fits all, but as a standard a name that has its origins in the Welsh language and where this is substantiated by either historic documentation and/or contemporary usage should be prioritised in favour of a contemporary anglicised or English version of the name.  Likewise, if a name exists where an element of it is in English and if this name applies to a hill that is situated in a Welsh speaking part of Wales it is standard practice to use a full Welsh term for the name.  It is also standard practice to use a Welsh name for a hill if another name exists that has originated in a different language.

Therefore, the name this hill is now listed by in the 30-99m Twmpau is Parc Penrhyn, with this name prioritised over the mixed language name favoured on the contemporary Ordnance Survey 1:25,000 Explorer map and the land name favoured over that of the castle name. 

 

The full details for the hill are:

Group:  Glyder Fawr

Name:  Parc Penrhyn

Previously Listed Name:  Penrhyn Castle 

OS 1:50,000 map:  115

Summit Height:  56.5m (LIDAR) 

Summit Grid Reference:  SH 60179 72091 (LIDAR)               

Bwlch Height:  31.5m (LIDAR) 

Bwlch Grid Reference:  SH 60168 71662 (LIDAR) 

Drop:  25.1m (LIDAR) 

 

Myrddyn Phillips (March 2025)