Monday, 5 March 2018

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


Allt y Ferin Nurseries (SN 518 228) – Lesser Dominant addition

There has been an addition to the listing of Y Trechol – The Dominant Hills of Wales, resulting in this hill being added to the Lesser Dominant list due to its drop value being amended.

The criteria for inclusion to the Dominant list being those Welsh P30 hills whose prominence equal or exceed half that of their absolute height, whilst the criteria for the Lesser Dominant list are those additional Welsh P30s whose prominence is 33% or more and below 50% of their absolute height.

During 2006 and 2007 the sub category of hills accompanying the Welsh P30 lists published on Geoff Crowder’s v-g.me website were standardised and interpolated drop values also added, this hill was then listed with an estimated c 29m of drop based on an estimated c 67m summit height and the 38m bwlch spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.  The drop value was subsequently altered to 31m due to a 69m summit spot height appearing on the Ordnance Survey Interactive Coverage Map hosted on the Geograph website.

The name of the hill is Allt y Ferin Nurseries and it is adjoined to the Mynydd Mallaen group of hills which are situated in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is positioned above the Afon Cothi which is to its north, and it has the small community of Llanegwad towards the south.

As the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so the nearest access point of convenience is a minor road towards the south-east of hill’s summit.

The qualification of Allt y Ferin Nurseries to Lesser Dominant status is dependent upon Ordnance Survey spot heights, with a summit spot height of 69m given on the Interactive Coverage map hosted on the Geograph website and a bwlch spot height of 38m given on the 1:50,000 Landranger and 1:25,000 Explorer map, with these values giving this hill 31m of drop and 44.93% Dominance, which is sufficient for this hill to be listed as a Lesser Dominant hill.


The full details for the hill are:

Group:  Mynydd Mallaen

Name:  Allt y Ferin Nurseries

Dominance:  44.93%

OS 1:50,000 map:  159

Summit Grid Reference:  SN 51824 22804

Summit Height:  69m

Drop Summit to Bwlch:  31m

Drop Bwlch to ODN:  38m 



Myrddyn Phillips (March 2018)






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