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

Pt. 328m (SN 676 358) – Sub-Trichant addition

There has been 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 maps produced from Ordnance Survey data. 

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 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 being listed by the point (Pt. 328m) 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 Mallaen group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and south, the B4302 road to its north-west, and the A482 farther to its east, and has the town of Llanymddyfri (Llandovery) 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, 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 and it was listed with an estimated c 20m of drop, based on the 328m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 308m bwlch height, based on interpolation of 10m contouring between 300m – 310m.

Therefore, the addition of this hill to Sub-Trichant status is due to detail on contemporary maps produced from Ordnance Survey data, resulting in a 328m summit height and an estimated c 308m bwlch height, with these values giving this hill an estimated c 20m of drop, which is sufficient for it to be classified as a Sub-Trichant. 

 

The full details for the hill are: 

Group:  Mynydd Mallaen 

Name:  Pt. 328m 

OS 1:50,000 map:  146

Summit Height:  328m (spot height)                                                           

Summit Grid Reference:  SN 67676 35870 (spot height) 

Bwlch Height:  c 308m (interpolation) 

Bwlch Grid Reference:  SN 68426 35513 (interpolation) 

Drop:  c 20m (spot height summit and interpolated bwlch) 

 

Myrddyn Phillips (July 2023)