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

Pt. 335.0m (SJ 044 499) – 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 confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR summit image of Pt. 335.0m (SJ 044 499)

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 hill is being listed by the point (Pt. 335.0m) notation as an appropriate name for it either through local enquiry and / or historic research has not been found by the author, 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 B5105 road to its north, the A5 road to its south-west and the A494 road to its east, and has the village of Clawddnewydd towards the north-east and the town of Corwen 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 that accompanied the main P30 list, as it was considered not to meet the criteria then used for this sub category. 

When 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 with an estimated c 22m of drop, based on the 335m summit spot height and an estimated bwlch height of c 313m based on interpolation of 10m contouring between 310m – 320m that appear on the Ordnance Survey 1:25,000 Explorer map.

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

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR bwlch image for Pt. 335m

Therefore, the confirmation of the addition of this hill to Sub-Trichant status is due to LIDAR analysis, resulting in a 335.0m summit height and a 309.7m bwlch height, with these values giving this hill 25.4m 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:  Pt. 335.0m

OS 1:50,000 map:  116

Summit Height:  335.0m (LIDAR)

Summit Grid Reference:  SJ 04495 49942 (LIDAR)

Bwlch Height:  309.7m (LIDAR)

Bwlch Grid Reference:  SJ 04991 50477 (LIDAR)

Drop:  25.4m (LIDAR)

Myrddyn Phillips (July 2020)