Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales and 200m Twmpau

 

Murgwyn (SH 351 442) – Sub-Trichant reclassified to 200m Sub-Twmpau

There has been a reclassification of a hill from the list of Y Trichant – The 300m Hills of Wales to the list of 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 Murgwyn (SH 351 442)

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

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 name the hill is listed by is Murgwyn, and this was derived from local enquiry, and it is adjoined to the Yr Eifl group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with a minor road to its south-east and the B4417 road to its south, and has the village of Llithfaen towards the south south-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, with a summit height os 300m, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map, with an accompanying note stating; 302m on 1984 1:50000 map. 

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

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with 28m of drop, based on the aforementioned 302m summit spot height and the 274m 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 1:50,000 Landranger 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.

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available maps and for this hill a 299m spot height is given on its summit area. 

Extract from the interactive mapping hosted on the WalkLakes 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.

Therefore, the reclassification of this hill to 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 298.8m summit height and a 273.5m bwlch height, with these values giving this hill 25.3m of drop, with its height insufficient for it to be classified as a Sub-Trichant. 

 

The full details for the hill are: 

Group:  Yr Eifl 

Name:  Murgwyn 

OS 1:50,000 map:  123

Summit Height:  298.8m (LIDAR)                                                           

Summit Grid Reference:  SH 35132 44223 (LIDAR) 

Bwlch Height:  273.5m (LIDAR) 

Bwlch Grid Reference:  SH 35281 44017 (LIDAR) 

Drop:  25.3m (LIDAR) 

 

Myrddyn Phillips (August 2025)

 

 

Mapping Mountains – Significant Name Changes – Y Trichant – The 300m Hills of Wales

DUE TO SUBSEQUENT LIDAR ANALYSIS THIS HILL HAS BEEN RECLASSIFIED TO 200m SUB-TWMPAU STATUS

Murgwyn (SH 351 442)

There has been a Significant Name Change to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from spot heights on contemporary Ordnance Survey maps.

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

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.

The hill is adjoined to the Pen Llŷn group of hills, which are situated in the western part of North Wales (Region A, Sub-Region A1), and it is positioned with the coast to its north-west and the B4417 to its south-east, and has the village of Llithfaen towards the south.

The hill appeared in the original Welsh 300m P30 list on Geoff Crowder’s v-g.me website under the name of Gallt y Bwlch, which is a prominent name that appeared close to the summit of this hill on contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps of the day.

Gallt y Bwlch

300m

SH351442

123

253/254

302m on 1984 1:50000 map

During my early hill listing I paid little regard to name placement on the map, or the meaning of names and to what feature the name was appropriately applied to.  Therefore I prioritised names for listing purposes that I now understand are either inappropriate or where another name is viewed as being more appropriate.

Extract from the Ordnance Survey 1:50,000 Landranger map

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.

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 814 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as Murgibn Ucha in the apportionments, with the details on the Tithe map appearing in the parish of Pistyll in the county named as Carnarvonshire [sic].

Extract from the apportionments

When researching the data in this and other lists I made extensive place-name enquiries with a number of local farmers, gamekeepers, landowners and academics and it was during this process that I contacted Paul Worsley who lives at the farm of Bwlch (SH 347 434).  At the time of our conversation Paul was aged 66 and had grazed sheep on this hill all of his adult life, with his family having lived at this farm for over 100 years.  Paul told me that the hill is known as Murgwyn and this name was passed down to him by his uncle. 

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Murgwyn, and this was derived from local enquiry, and in all likelihood the meaning of the Tithe name of Murbign is similar, if not the same to that of Murgwyn, and as the latter has come from a contemporary local source it is this name that is being used for that of the hill.

The full details for the hill are:

Group:  Pen Llŷn

Name:  Murgwyn

Previously Listed Name:  Gallt y Bwlch

OS 1:50,000 map:  123

Summit Height:  302m (spot height)

Summit Grid Reference:  SH 35128 44215 (spot height)

Bwlch Height:  274m (spot height)

Bwlch Grid Reference:  SH 35270 44043 (spot height)

Drop:  28m (spot heights)

Myrddyn Phillips (January 2020)