Mapping Mountains – Significant Name Changes – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

Llain Fawr (SN 428 202)

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, its location and drop of the hill initially confirmed by LIDAR analysis and subsequently by a summit survey with the Trimble GeoXH 6000 which were conducted by Myrddyn Phillips, with latter taking place on the 31^st July 2018.

Llain Fawr (SN 428 202)

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

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

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 addition Welsh P30 hills whose prominence is 33.33% or more and below 50% of their absolute height, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

LIDAR image of Llain Fawr

The hill is adjoined to the Mynydd Sylen group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and is positioned with the Afon Tywi (River Towy) and the A 40 to the north-west, and the B 4300 to the south, and has the town of Caerfyrddin (Carmarthen) towards the west.

The hill originally appeared in the 30-99m P30 list on Geoff Crowder’s v-g.me website under the name of Tan-yr-allt. 

Tan-yr-allt

81m

SN429202

159

177

During my early hill listing I 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.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose a farm name for that of the hill.  This is not a practice that I now advocate 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

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 589 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 Llainfawr in the apportionments, with the details on the Tithe map appearing in the parish of Llangunnor and in the county named as Carmarthen.

Extract from the apportionments

Therefore, the name this hill is now listed by in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales is Llain Fawr, and this was derived from the Tithe map.

The full details for the hill are:

Group:  Mynydd Sylen

Name:  Llain Fawr

Previously Listed Name:  Tan-yr-allt 

OS 1:50,000 map:  159

Summit Height:  80.8m (converted to OSGM15)

Summit Grid Reference:  SN 42855 20265

Bwlch Height:  23.om (LIDAR)

Bwlch Grid Reference:  SN 42905 19831 (LIDAR)

 

Drop:  57.8m (Trimble summit and LIDAR bwlch)

Dominance:  71.49% (Trimble summit and LIDAR bwlch)

Myrddyn Phillips (January 2019)

Mapping Mountains – Trimble Surveys – Mynydd Sylen

31.07.18  Llain Fawr (SN 428 202)

Llain Fawr (SN 428 202)

Llain Fawr is only a small heighted hill, but it is easily picked out from adjacent hills to its south which I had visited earlier in the day.  It sits above the small community of Llangunnor, its Church and Chuch Farm and the car park for the Church gives easy access to its summit.

Prior to visiting I’d analysed this hill’s summit and bwlch via LIDAR and come prepared with the ten figure grid reference for its summit.

LIDAR image of the summit of Llain Fawr

LIDAR image of the bwlch of Llain Fawr

It was only a few minutes’ walk up the remainder of the car park to a gate which gives access to the top field, a vehicle track led across the south-eastern flank of the field and I followed this until near the boundary hedge close to the summit of the hill.

Once the Trimble was positioned atop my rucksack to give it elevation above its immediate surrounds and the 0.1m accuracy level attained before data should be logged, I pressed ‘Log’ and stood back looking south toward the hills I had visited earlier in the day.

The sound of the beep, beep, beep of the equipment as each datum point is collected quietly blew in the afternoon’s breeze as I stood looking out at a land that I had not previously visited.  This part of P30 bagging when new land is visited signifies a form of investigation and for me this brings a sense of fulfilment.

Gathering data at the summit of Llain Fawr

The Trimble set-up position at the summit of Llain Fawr

Once the allotted data were gathered and stored I packed the equipment away and headed back to my car to change out of my walking gear and drive the short distance to Caerfyrddin (Carmarthen), where I was staying the night with a friend who was house sitting for one of her friends.  Tomorrow we had planned a six hill bagging road trip to enjoy.

Survey Result:  

Llain Fawr (significant name change)

Summit Height:  80.8m (converted to OSGM15)

Summit Grid Reference:  SN 42855 20265

Bwlch Height:  23.0m (LIDAR)

Bwlch Grid Reference:  SN 42905 19831 (LIDAR)

Drop:  57.8m (Trimble summit and LIDAR bwlch)

Dominance:  71.49% (Trimble summit and LIDAR bwlch)

For further details please consult the Trimble Survey Spreadsheet