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

Pt. 22.2m (SM 701 226) – Pellennig addition

There has been an addition to the listing of Y Pellennig – The Remotest Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Aled Williams.

Pt. 22.2m (SM 701 226)

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

Y Pellennig – The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and is available as a downloadable e-bookletor print-booklet version on Mapping Mountains Publications with the up-to-date master list available on the Mapping Mountains site in Google Doc format.

As the authors do not know an appropriate name for this hill either from historic research or local enquiry it is being listed by the point (Pt. 22.2m) notation, and it is adjoined to the Carn Llidi group of hills which are situated in the south-western part of Mid and West Wales (Region B, Sub-Region B4), and it is positioned in a small sheltered bay on the southern side of Ynys Dewi.

This hill was not included when the original list of Pellennig hills was compiled as contemporary Ordnance Survey 1:25,000 Explorer maps do not give it any contour ring.  The lack of contour rings is also applicable to the Ordnance Survey Vector Map Local hosted on the Geograph website which is entitled the Interactive Coverage Map.

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

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website

The details for this hill were re-assessed when the OS Maps website became available online.  This is the replacement for OS Get-a-map and has 5m contour intervals.  This mapping gives this hill an uppermost 15m ring contour, but as this hill is adjoined to its southerly counterpart which is already listed as a Pellennig hill by a connecting bwlch higher than 5m it implies that its drop is less than the minimum 15m required for it to be considered for Pellennig status.

Extract from the OS Maps website

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR image of Pt. 22.2m; 1m contour (black), 10m contour (red) and sea level (yellow)

Close up LIDAR image of Pt. 22.2m; 1m contour (black), 10m contour (red) and sea level (yellow)

The addition of this hill to Pellennig status is due to LIDAR analysis, resulting in a 22.2m summit height and confirmation that this is also its drop value as the connecting bwlch is below sea level, and with the distance between its summit and the nearest paved public road being 3.400km, it gives this hill sufficient remoteness and drop for Pellennig status.

The full details for the hill are:

Group:  Carn Llidi

Name:  Pt. 22.2m

OS 1:50,000 map:  157

Summit Height:  22.2m (LIDAR)

Summit Grid Reference:  SM 70180 22696 (LIDAR)

Bwlch Height:  N/A, sea level

Bwlch Grid Reference:  N/A, sea level 

  

Drop:  22.2m (LIDAR)

Remoteness:  3.400km

For the additions and deletions to Y Pellennig – The Remotest Hills of Wales reported on Mapping Mountains please consult the following Change Register:

Y Pellennig – The Remotest Hills of Wales

Myrddyn Phillips and Aled Williams (June 2019)

© Crown: CHERISH PROJECT 2019. Produced with EU funds through the Ireland Wales Co-operation Programme 2014-2020. All material made freely available through the Open Government Licence.