Mapping Mountains – Significant Name Changes – 200m Twmpau

Cae Tŷ Coch (SO 095 413) 

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 Cae Tŷ Coch (SO 095 413)

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, 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 Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned with a minor road to its west and south-east, and the A470 road to its north-east, and has the small community of Erwyd (Erwood) towards the north.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After 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 under the point (Pt. 282m) notation with an estimated c 20m of drop, based on the 282m summit spot height that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 262m bwlch height, based on interpolation of 10m contouring between 260m – 270m. 

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 757 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 Cae Tŷ Coch in the apportionments, with the details on the Tithe map appearing in the parish of Crucadarn and in the county named as Brecon. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 200m Twmpau is Cae Tŷ Coch, and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Mynydd Epynt

Name:  Cae Tŷ Coch

Previously Listed Name:  Pt. 282m   

OS 1:50,000 map:  161

Summit Height:  282.7m (LIDAR) 

Summit Grid Reference:  SO 09549 41332 (LIDAR) 

Bwlch Height:  260.65m (LIDAR) 

Bwlch Grid Reference:  SO 09124 41273 (LIDAR) 

Drop:  22.0m (LIDAR) 

 

Myrddyn Phillips (September 2024) 

Mapping Mountains – Significant Height Revisions – The Welsh P15s

Y Boncyn (SH 532 398) 

There has been a Significant Height Revision to a hill that is listed in The Welsh P15s, 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 Y Boncyn (SH 532 398)

The criteria for the list that this height revision applies to are:

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

The name the hill is listed by is Y Boncyn, and it is adjoined to the Moel Hebog group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the A487 road to its north and the A497 road to its south, and has the town of Porthmadog towards the east south-east.

When the listing that became known as The Welsh P15s was being compiled, this hill was not included in the main P15 or Sub P14 list, as with no significant contours of note on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, it was difficult to know whether any hill of note existed. 

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

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. 

LIDAR summit image of Y Boncyn (SH 532 398)

The summit height produced by LIDAR analysis is 66.3m and when compared to detail on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 66.3m and this was derived from LIDAR analysis.  This is 16.3m higher than the uppermost 50m contour that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map. 

 ills of Wales, and are reproduced below@

The full details for the hill are: 

Group:  Moel Hebog 

Name:  Y Boncyn 

OS 1:50,000 map:  124

Summit Height (New Height):  66.3m (LIDAR)                                                           

Summit Grid Reference:  SH 53275 39885 (LIDAR) 

Bwlch Height:  51.0m (LIDAR) 

Bwlch Grid Reference:  SH 53321 39934 (LIDAR) 

Drop:  15.3m (LIDAR) 

 

Myrddyn Phillips (September 2024)

 

  

Mapping Mountains – Summit Relocations – 100m Twmpau

 

Pt. 162.1m (SN 508 034) 

There has been a Summit Relocation to a hill that is listed in the 100m 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 Pt. 162.1n (SN 508 034)

The criteria for the list that this summit relocation applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height that have 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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. 

100m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 162.1m) notation and it is adjoined to the Mynydd Sylen group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with a minor road and the B4309 road to its west and a minor road and the A476 road to its east, and has the town of Llanelli towards the south.

When the original 100m 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 with a 161m summit height, based on the spot height positioned on a minor road that appears at SN 50822 03406 on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with 23m of drop, based on the 161m summit spot height and the 138m 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 1:25,000 Explorer map

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.

LIDAR analysis gives the highest ground on this hill as 102.6m positioned at SN 50798 03441.  However, this is to the top of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Pt. 162.1m (SN 508 034)

The height produced by LIDAR analysis to the natural summit of this hill is 162.1m and is positioned at SN 50860 03434 and SN 50868 03434, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is judged to be a relatively recent man-made construct, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist.

Therefore, the height produced by LIDAR analysis to the natural summit of this hill is 162.1m and is positioned at SN 50860 03434 and SN 50868 03434, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 62 metres eastward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Mynydd Sylen 

Name:  Pt. 162.1m 

OS 1:50,000 map:  159

Summit Height:  162.1m (LIDAR) 

Summit Grid Reference (New Position):  SN 50860 03434 & SN 50868 03434 (LIDAR) 

Bwlch Height:  138.2m (LIDAR) 

Bwlch Grid Reference:  SN 50307 03907 (LIDAR) 

Drop:  23.9m (LIDAR) 

 

Myrddyn Phillips (September 2024)

 

Mapping Mountains – Hill Reclassifications – 30-99m Twmpau

Bigyn (SS 512 998) – 30-99m Sub-Twmpau addition 

There has been an addition to the list of 30-99m 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 Bigyn (SS 512 998)

The criteria for the list that this addition applies to are:

30-99m Twmpau – Welsh hills at or above 30m and below 100m in height that have 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. 

30-99m Twmpau by Myrddyn Phillips

The name the hill is listed by is Bigyn and it is adjoined to the Mynydd Sylen group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with the A484 road to its north and the B4304 road to its south, and has the town of Llanelli surrounding it.

When the original 30-99m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After 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 an estimated c 16m of drop, based on the 43m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, and an estimated c 27m bwlch height, based on interpolation of 5m contouring between 25m – 30m. 

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

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 addition of this hill to 30-99m Sub-Twmpau status is due to LIDAR analysis, resulting in an 45.8m summit height and a 20.7m bwlch height, with these values giving this hill 25.1m of drop, which is sufficient for it to be classified as a 30-99m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Sylen 

Name:  Bigyn 

OS 1:50,000 map:  159

Summit Height:  45.8m (LIDAR) 

Summit Grid Reference:  SS 51218 99827 (LIDAR)               

Bwlch Height:  20.7m (LIDAR) 

Bwlch Grid Reference:  SN 51552 00728 (LIDAR) 

Drop:  25.1m (LIDAR) 

 

Myrddyn Phillips (September 2024)

  

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

 

Mynydd Llandyfalle (SO 088 361) 

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 LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mynydd Llandyfalle (SO 088 361)

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 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

The hill is adjoined to the Mynydd Epynt group of hills, which are situated in the central part of South Wales (Region B, Sub-Region B1), and it is positioned encircled by minor roads, with the B4520 road farther to its west, the A470 road farther to its south, east and north-east, and has the town of Talgarth towards the east 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 not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category.

After 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 under the point (Pt. 347m) notation with an estimated c 20m of drop, based on the 347m summit spot height that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 327m bwlch height, based on interpolation of 10m contouring between 320m – 330m. 

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 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 historic maps now available online is 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 Draft Surveyors map that has instigated the change in the listed name of this hill. 

Extract from the Ordnance Survey Draft Surveyors map

The Draft Surveyors maps consist of the preliminary drawings made by the Ordnance Survey surveyors between the 1780s and 1840 and formed the basis for the first publicly available One-Inch map.  They were drawn at scales of six inches to the mile for areas considered of particular military significance and down to two inches to the mile for other areas.  Fair copies were then produced from these preliminary drawings to one inch to the mile and then copper plates were prepared for printing.  The Draft Surveyors maps for the whole of Wales are now available online and they form an important part in the study of Welsh upland place-names as they bridge the time frame between the late 18^th century and the mid-19^th century when the Ordnance Survey produced their first One-Inch maps, and importantly for this hill and its listed name, it is this map that places the name Mynydd Llandyfalle across what is now open access land and which takes in the summit of this hill.

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Mynydd Llandyfalle and this was derived from the Ordnance Survey Draft Surveyors map. 

 

The full details for the hill are: 

Group:  Mynydd Epynt 

Name:  Mynydd Llandyfalle 

Previously Listed Name:  Pt. 347m 

OS 1:50,000 map:  160

Summit Height:  347.7m (LIDAR)                                                           

Summit Grid Reference:  SO 08800 36195 (LIDAR) 

Bwlch Height:  327.1m (LIDAR) 

Bwlch Grid Reference:  SO 08140 36189 (LIDAR) 

Drop:  20.6m (LIDAR) 

 

Myrddyn Phillips (September 2024)