Sunday, 11 December 2016

Mapping Mountains – Hill Reclassifications – Y Pellennig – The Remotest Hills of Wales


Esgair y Llyn (SN 841 701) - Pellennig addition

There has been a new hill that has entered the list of Y Pellennig – The Remotest Hills of Wales, due to detail on the Ordnance Survey enlarged mapping on the Geograph website aided by analysis of LIDAR data by Aled Williams.  The hill is situated in the Elenydd group of hills which are positioned in the central part of the Region of Mid and West Wales.

This grouping of hills forms one of the wildest in Wales and takes in some of the most remote hills in the country.  The hill is situated in an immense grassland of moor and tussocks with Llyn Cerrigllwydion Isaf to its south-east and the higher summits of Cnapyn Drawsffos (SN 834 706) to its north-west and Blaen Rhestr (SN 843 693) towards its south.  Any towns or villages are a far distance away with Ysbyty Ystwyth towards the west and Rhaeadr Gwy (Rhayader) towards the east.

The hill can be accessed from its north-east via a track that leads to the farmhouse of Glanhirin, a path then leads toward and up the north-eastern ridge of Blaen Rhestr.  However, an alternate route is from the east north-east via the Monks Trod, which is an ancient route across the hills developed by the Cistercian monks as a bi-way between the abbeys of Cwm-Hir and Strata Florida.  Whichever way is chosen it leads into land that is open and featureless, and when visiting the hill a day comprising good weather is highly recommended.

The name of the hill is Esgair y Llyn and its inclusion as a Pellennig was spotted by Aled as the Ordnance Survey enlarged mapping on the Geograph website gives this hill a 529m summit spot height and a 513m bwlch spot height, these values give the hill 16m of drop which is sufficient to enter the list of Pellennig hills with the caveat of the distance from the hill’s summit to the nearest paved public road being a minimum of 2.5km.  As Aled was analysing other hills in the vicinity against LIDAR data, he did likewise with Esgair y Llyn.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gave the hill a 528.8m summit height at SN 84118 70177, and a 513.3m bwlch height at SN 83811 70087, these values give this hill 15.5m of drop which is sufficient when coupled with its summit being 4.535km from the nearest paved public road for qualification as a Pellennig hill.

This now brings the overall total for Y Pellennig to 169 hills for the Complete list (All Wales), with the total for the Mainland Wales list being 125 hills.  The Master List will be duly updated on the Mapping Mountains site.


The full details for the hill are:

Cardinal Hill:  Carny yr Hyrddod

Summit Height:  528.8m (LIDAR data)

Name:  Esgair y Llyn

OS 1:50,000 map:  135, 136, 147

Summit Grid Reference:  SN 84118 70177
     
Drop:  15.5m (LIDAR data)

Distance:  4.535km


The list of additions and deletions in the Pellennig list since the 1st edition of Y Pellennig – The Remotest Hills ills of wales of Wales was published by Europeaklist (1st edition, April 2015) is as follows:


ADDITIONS




Esgair y Llyn (LIDAR data) (SN 841 701)



DELETIONS







Myrddyn Phillips and Aled Williams (December 2016)





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