Mapping Mountains – Significant Name Changes – Y Trichant – The 300m Hills of Wales

Bryniau Gwenllian (SJ 001 139) 

There has been a Significant Name Change to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data. 

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned with a minor road to its south-west, the A458 road farther to its south-west and the B4395 road to its east, and has the village of Llangadfan towards the south south-east.

When the original 300m 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 point (Pt. c 355m) notation with an estimated c 20m of drop, based on an estimated c 355m summit height and an estimated c 335m bwlch height, with both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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, and importantly for this hill and its listed name, it is this map that names the land taking in the summit of this hill as Bryniau Gwen Llwyn. 

Extract from the Tithe map

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Bryniau Gwenllian and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Esgeiriau Gwynion 

Name:  Bryniau Gwenllian 

Previously Listed Name:  Pt. c 355m 

OS 1:50,000 map:  125 

Summit Height:  358m (spot height)                                                           

Summit Grid Reference:  SJ 00115 13999 (spot height) 

Bwlch Height:  c 336m (interpolation) 

Bwlch Grid Reference:  SJ 00435 14248 (interpolation) 

Drop:  c 22m (spot height summit and interpolated bwlch) 

 

Myrddyn Phillips (June 2022)