Mapping Mountains – Hill Reclassifications – Y Trechol – The Dominant Hills of Wales

Pantau (SN 648 226) – Lesser Dominant deletion

There has been a deletion to the listing of Y Trechol – The Dominant Hills of Wales, with the summit height, its location, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Pantau

The criteria for the list that this reclassification applies to are:

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

When the original Welsh 100m P30 list that was published on Geoff Crowder’s v-g.me website was standardised and interpolated height and drop vales added, this hill was listed with c 41m of drop based on an estimated c 118m summit height and an estimated c 77m bwlch height.

These values were re-assessed when the Ordnance Survey Interactive Coverage Map hosted on the Geograph website became available online, and this map gives this hill a 117m summit spot height and a 77m spot height on the area of its bwlch, with these values giving this hill 40m of drop and 34.19% dominance.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website

The name of the hill is Pantau and it is adjoined to the Y Mynydd Du group of hills, which are situated in the north-western part of South Wales (Region C, Sub-Region C1), and it is positioned with the Afon Tywi (River Towy) and the A40 road to its north-west, and has the small town of Llandeilo towards the west.

If wanting to visit the hill permission to do so should be sought as the summit area is not a part of designated open access land and has no public footpaths that approach it, for those wishing to do so an approach from the convenience of a minor road towards the south may be the best option.

The summit height produced by LIDAR analysis is 115.8m and is positioned at SN 64809 22669 and SN 64816 22665, and the bwlch height is 77.3m and is positioned at SN 65097 22612, with these values giving this hill 38.6m of drop and 33.31% dominance, which is insufficient for this hill to be classified as a Lesser Dominant.

The full details for the hill are:

Group:  Y Mynydd Du

Name:  Pantau

OS 1:50,000 map:  159

Summit Grid Reference:  SN 64809 22669 and SN 64816 22665 (LIDAR)

Summit Height:  115.8m (LIDAR)

Bwlch Grid Reference:  SN 65097 22612 (LIDAR)

Drop Summit to Bwlch:  38.6m (LIDAR)

Drop Bwlch to ODN:  77.3m (LIDAR)

Dominance:  33.31% (LIDAR)

Myrddyn Phillips (February 2019)