Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

Ffridd Fawr (SH 911 637) – Sub-Trichant addition

There has been confirmation of an addition to the list of 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 Ordnance Survey maps.

The criteria for the list that this addition 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 13th May 2017.

The name the hill is listed by is Ffridd Fawr and this was derived from the Tithe map, and it is adjoined to the Mynydd Hiraethog group of hills which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the B5384 road to its north-west and the A544 road to its east, and has the village of Llansannan towards the north-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 that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated against the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and included a 309m summit and 289m bwlch spot height for this hill.  These spot heights are also shown on Ordnance Survey data that appears on the Magic Maps website.

Extract from the Magic Maps website

Therefore, the addition of this hill to Sub-Trichant status is due to detail derived from the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map, with this detail also shown on the Magic Maps website, resulting in a 309m summit height and a 289m bwlch height, with these values giving this hill 20m of drop, which is sufficient for it to be classified as a Sub-Trichant.

The full details for the hill are:

Group:  Mynydd Hiraethog

Name:  Ffridd Fawr

OS 1:50,000 map:  116

Summit Height:  309m (spot height)

Summit Grid Reference:  SH 91105 63732 (spot height)

Bwlch Height:  289m (spot height)

Bwlch Grid Reference:  SH 91260 63693 (spot height)

Drop:  20m (spot height summit and bwlch)

Myrddyn Phillips (April 2020)