Mapping Mountains – Significant Name Changes – Y Pedwarau – The 400m Hills of Wales and Y Trechol – The Dominant Hills of Wales

Gwastedyn (SN 986 661)

There has been a Significant Name Change to a hill that is listed in the Y Pedwarau – The 400m Hills of Wales and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill confirmed by LIDAR analysis initially conducted by Aled Williams.

LIDAR image of Gwastedyn (SN 986 661)

The criteria for the two listings that this name change applies to are:

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height with 30m minimum drop, the list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

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, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The hill is adjoined to the Hirddywel group of hills, which are situated in the north-eastern part of Mid and West Wales (Region B, Sub-Region B1), and it is positioned with the A44 road to its north-east and the A470 road to its south-west, and has the town of Rhaeadr Gwy (Rhayader) towards the north-west.

The hill appeared in the original Welsh 400m P30 list on Geoff Crowder’s v-g.me website under the name of Gwastedyn Hill, which is a prominent name that appears beside the summit of this hill on contemporary Ordnance Survey maps.  This is also the name the hill was listed by in the 1^st edition of the Y Pedwarau published by Europeaklist in May 2013.

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

Since publication of the 1^st edition of Y Pedwarau 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 Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.  Two of the historic maps now available are the Ordnance Survey Draft Surveyors map which formed the basis for the first publicly available Ordnance Survey One-Inch ‘Old Series’ map and the latter map and the Ordnance Survey Six-Inch map form the basis for the change in this hill’s listed name.

Extract from the Ordnance Survey One-Inch 'Old Series' map

The One-Inch ‘Old Series’ map was the first map that the Ordnance Survey produced, and their publication culminated from the whole of Britain being surveyed between 1791 and 1874 and the detail gathered therein produced at a scale of one inch to the mile and published in sheet format between 1805 and 1874.  The One-Inch ‘Old Series’ maps for the whole of Wales are now available online; they are also available in map format as enlarged and re-projected versions to match the scale and dimensions of the Ordnance Survey 1:50,000 Landranger series and are published by Cassini.  This series of maps form another important part in the study of Welsh upland place-names and bridge the timeframe leading up to the production of the Ordnance Survey base map of the Six-Inch series, and it is these two maps that use the form of this hill’s name without the word Hill, which is a relatively recent map addition.

Extract from the Ordnance Surveys series of Six-Inch maps

Therefore, the name this hill is now listed by in the Y Pedwarau – The 400m Hills of Wales and Y Trechol – The Dominant Hills of Wales is Gwastedyn and this form without the superfluous use of the word Hill was derived from the Ordnance Survey One-Inch ‘Old Series’ map and the Ordnance Survey series of Six-Inch maps and substantiated by the 1865 Enclosure Map.

The full details for the hill are:

Group:  Hirddywel

Name:  Gwastedyn

Previously Listed Name:  Gwastedyn Hill

OS 1:50,000 map:  136, 147

Summit Height:  477.2m (LIDAR)

Summit Grid Reference:  SN 98679 66145 (LIDAR)

Bwlch Height:  233.1m (LIDAR)

Bwlch Grid Reference:  SN 99395 68804 (LIDAR)

Drop:  244.1m (LIDAR)

Dominance:  51.15% (LIDAR)

Myrddyn Phillips and Aled Williams (November 2019)