Mapping Mountains – Significant Name Changes – Y Pedwarau - The 400m Hills of Wales

Garwyd (SH 996 459)

There has been a Significant Name Change to a hill that is listed in the Y Pedwarau – The 400m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Garwyd (SH 996 459)

The criteria for the list 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 that have 30m minimum drop, accompanying the main list are five categories of sub hills; 500m Sub-Pedwarau, 500m Double Sub-Pedwarau, 400m Sub-Pedwarau, 390m Sub-Pedwarau and the 390m Double Sub-Pedwarau.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format. 

Y Pedwarau - The 400m Hills of Wales by Myrddyn Phillips and Aled Williams

The hill is adjoined to the Mynydd Hiraethog group of hills, which are situated in the north-eastern part of North Wales (Region C1, Sub-Region C1A), and it is positioned with the A5 road and the Afon Ceirw to its south, and has the village of Cerrigydrudion towards the west north-west and the town of Corwen towards the east south-east.

The hill appeared in the original Welsh 400m P30 list compiled by Myrddyn Phillips and published on Geoff Crowder’s v-g.me website, under the transposed name of Cader Dinmael, which is a prominent name that appears just to the south of the summit of this hill on the contemporary Ordnance Survey 1:25,000 Explorer map.

Cader Dinmael

452m

SH997459

116

255/264

The composition of the name was subsequently amended to Cadair Dinmael to reflect the use of standard modern Welsh.  However, when Myrddyn Phillips first compiled this list he thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  His preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose a name that appeared near the summit of this hill on the contemporary Ordnance Survey 1:25,000 Explorer map.  This is not a practice that he now advocates as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found.

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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of 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 were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites.  Two of the historic maps now available online are the Ordnance Survey Draft Surveyors map which formed the basis for the first publicly available Ordnance Survey One-Inch ‘Old Series’ map, and it is the latter of these two maps in conjunction with the Ordnance Survey series of Six-Inch maps that form the basis of the change in the listed name of this hill.

The One-Inch ‘Old Series’ map was the first map that 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 importantly for this hill and its listed name, it is this map that places the name Garwyd adjacent to the summit of this hill and places the name of Cadair Dinmael adjacent to 470.6m high hill positioned at SH 98947 46976.

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

The Ordnance Survey series of Six-Inch maps formed the base map Ordnance Survey used for many decades leading to the production of the 1:10,000 Series of maps, both have now been superseded by the digitised Master Map.  The series of Six-Inch maps are excellent for name placement and especially so compared to the contemporary Ordnance Survey 1:25,000 Explorer map, and it is also the series of Six-Inch maps that places the name of Garwyd adjacent to the summit of this hill.

Extract from the Ordnance Survey series of Six-Inch maps

Therefore, the name this hill is now listed by in the Y Pedwarau – The 400m Hills of Wales is Garwyd, and this was derived from the Ordnance Survey One-Inch 'Old Series' map and the Ordnance Survey series of Six-Inch maps.

The full details for the hill are:

Group:  Mynydd Hiraethog

Name:  Garwyd

Previously Listed Name:  Cadair Dinmael

OS 1:50,000 map:  116

Summit Height:  454.1m (LIDAR)

Summit Grid Reference:  SH 99674 45906 (LIDAR)

Bwlch Height:  418.5m (LIDAR)

Bwlch Grid Reference:  SH 99403 46478 (LIDAR)

Drop:  35.6m (LIDAR)

Myrddyn Phillips and Aled Williams (October 2019)