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

Ysgeibion (SJ 060 589) – 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 Ysgeibion 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 encircled by minor roads with the B4501 road further to its north-west, the B5105 road further to its south-east and the A525 road further to its north-east, and has the town of Rhuthun (Ruthin) towards the 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 c 21m of drop, based on the 338m spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 317m bwlch height based on interpolation of 5m contouring between 315m – 320m.

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

Another resource now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available maps and shows a 339m spot height on the summit area of this hill.  However, for this hill the 338m spot height shown on the Ordnance Survey 1:25,000 Explorer map is being prioritised.

Extract from the WalkLakes website

Therefore, the addition of this hill to Sub-Trichant status is due to detail derived from contemporary Ordnance Survey maps, resulting in a 338m summit height and a c 317m bwlch height, with these values giving this hill an estimated c 21m 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:  Ysgeibion

OS 1:50,000 map:  116

Summit Height:  338m (spot height)

Summit Grid Reference:  SJ 06079 58984 (spot height)

Bwlch Height:  c 317m (interpolation)

Bwlch Grid Reference:  SJ 05734 59177 (interpolation)

Drop:  c 21m (spot height summit and interpolated bwlch)

Myrddyn Phillips (April 2020)