Mapping Mountains – Significant Name Changes – 200m Twmpau

 

Moel Hiraddug (SJ 063 781) 

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau, 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 Moel Hiraddug (SJ 063 781)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

200m Twmpau by Myrddyn Phillips

The hill is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with minor roads to its north-east, west and south, and the A5151 road to its north, and has the village of Dyserth towards the north-west.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the main list under the transposed name of Y Foel, with an accompanying note stating; aka Mynydd Hiraddug.

Y Foel

265m

SJ063782

116

264/265

aka Mynydd Hiraddug

As both names are recorded by Ordnance Survey and as the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales.  The enclosed land where the summit of this hill is situated is named as Moel Hiraddug on the Tithe. 

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, and it is the series of Ordnance Survey Six-Inch maps in conjunction with contemporary Ordnance Survey mapping and the Tithe map that form the basis in the prioritised listed name of this hill. 

Extract from the Tithe 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 the series of Six-Inch maps that position the name of Moel Hiraddug 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 200m Twmpau is Moel Hiraddug, and this was derived from the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map in conjunction with the Tithe map and the Ordnance Survey series of Six-Inch maps. 

 

The full details for the hill are:

Group:  Moel y Gamelin

Name:  Moel Hiraddug

Previously Listed Name:  Y Foel   

OS 1:50,000 map:  116

Summit Height:  264.4m (LIDAR) 

Summit Grid Reference:  SJ 06369 78199 (LIDAR) 

Bwlch Height:  186.0m (LIDAR) 

Bwlch Grid Reference:  SJ 06724 77888 & SJ 06727 77887 & SJ 06731 77883 & SJ 06736 77881 (LIDAR) 

Drop:  78.5m (LIDAR) 

 

Myrddyn Phillips (December 2025)