Mapping Mountains – Significant Name Changes – The Welsh P15s

Marian Dyrys (SH 597 809) 

There has been a Significant Name Change to a hill that is listed in The Welsh P15s, 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 name change applies to are:

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is adjoined to the Ynys Môn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the coast to its north and is encircled by minor roads with the B5109 road farther to its south south-east, and has the village of Llanddona towards the south-west. 

When the listing that became known as The Welsh P15s was being compiled, this hill was listed under the point (Pt. 134m) notation with 17m of drop, based on the 134m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 117m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

Since the initial compilation of this list there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the mapping on the Magic Maps and WalkLakes websites. 

One of the mapping resources now online is the Ordnance Survey series of Six-Inch maps available on the National Library of Scotland website.  This mapping preceded the 1:10,000 base map and has proven an excellent resource for name placement, something that the publicly available Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps cannot proclaim.  And it is the Six-Inch map that places the name of Marian Dyrys adjacent to land taking in this hill and its summit. 

Extract from the Ordnance Survey series of Six-Inch maps

Therefore, the name this hill is now listed by in The Welsh P15s is Marian Dyrys and this derived from the Ordnance Survey series of Six-Inch maps. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Marian Dyrys

Previously Listed Name:  Pt. 134m 

OS 1:50,000 map:  114, 115

Summit Height:  134m (spot height) 

Summit Grid Reference:  SH 59715 80960 (spot height) 

Bwlch Height:  117m (spot height) 

Bwlch Grid Reference:  SH 59317 81154 (spot height) 

Drop:  17m (spot height summit and bwlch) 

 

Myrddyn Phillips (April 2021)