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

 

Tirlenwiad Bryn Posteg (SN 971 820) and Pt. 344.4m (SN 970 825) 

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 Tirlenwiad Bryn Posteg (SN 971 820)

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

Dual Summit hills:

A hill classified as a Dual Summit is defined as one which has an extant natural summit coupled with that of a higher artificial summit, with the latter that can be described as stable in character.  In the main, these recent man-made constructions are the result of quarrying activities producing spoil tips, or as in this instance a landfill.  These recent man-made constructions are treated differently to ancient man-made constructions such as hill forts and tumuli, as if the latter are deemed stable and of an earthen character their age dictates that they can be viewed as being permanent in nature and are now effectively a part of the hill.  For those bagging Dual Summit hills, a visit to either the natural high point or the elevated man-made high point is sufficient to claim an ascent of the hill.  With the Dual Summit classification being a relatively new category and fist instigated in January 2018 for a Dual Summit Pedwar.

The hill is adjoined to the Hirddywel group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its north-east and south-east, and the B4518 road to its south-west, and has the town of Llanidloes towards the north-west.

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 accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

Extract from the Ordnance Survey 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-evaluated and it was listed under the point (Pt. 345m) notation with an estimated c 26m of drop, based on the 345m summit spot height positioned at SN 97010 82528 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 319m bwlch height, based on interpolation of 10m contouring between 310m – 320m.

As the prioritised higher summit of this Dual Summit Hill has been terraformed and now comprises a landfill, online sites were investigated, resulting in a number of sources using the name of Bryn Posteg Landfill for this site.  This name matches that given by a number of local residents.  As this hill comprises a corporate site the listing protocol is used and a full Welsh term for the hill is therefore used.

Therefore, the name the prioritised higher summit is now listed by in the Y Trichant – The 300m Hills of Wales is Tirlenwiad Bryn Posteg and this was derived from online sources. 

 

The full details for the hill are: 

Group:  Hirddywel 

Name:  344.4m (natural Dual Summit) and Tirlenwiad Bryn Posteg (artificial Dual Summit)

Previously Listed Name:  Pt. 345m 

OS 1:50,000 map:  136

Summit Height:  344.4m (natural Dual Summit) (LIDAR) and 351.9m (artificial Dual Summit (LIDAR)

Summit Grid Reference (New Position):  SN 97023 82535 (natural Dual Summit) (LIDAR) and SN 97109 82092 & SN 97114 82098 (artificial Dual Summit) (LIDAR)

Bwlch Height:  331.0m (LIDAR)

Bwlch Grid Reference:  SN 97021 81849 (LIDAR)

Drop:  13.4m (natural Dual Summit) (LIDAR) and 20.9m (artificial Dual Summit) (LIDAR)

 

My thanks to Aled Williams for advise relating to the listed name of this hill

Myrddyn Phillips (August 2025)

 

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

Hafoty Glan y Bala (SH 587 610) 

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 Hafoty Glan y Bala (SH 587 610)

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 Glyder Fawr group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with minor roads to its north-west and east, the A4086 road to its south-west, and has the village of Llanberis towards the south-west.

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 accompanying Hills to be surveyed sub list, as with a 313m summit spot height on the contemporary Ordnance Survey 1:25,000 Explorer map and with no significant bwlch contours of note it was difficult to know whether any hill of note existed.

Current online Ordnance Survey mapping now shows bwlch contouring between 285m – 290m, and therefore this hill was listed under the point (Pt. 313m) notation with interpolation placing the height of the bwlch at an estimated c 289m and when coupled with the 313m summit spot height, these values gave this hill an estimated c 24m of drop. 

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 198 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 transcribed as Glan y Bala Hafoty in the apportionments, with the details on the Tithe map appearing in the parish named as Llanddeiniolen and in the county named as Caernarfon. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Hafoty Glan y Bala and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Glyder Fawr 

Name:  Hafoty Glan y Bala 

Previously Listed Name:  Pt. 313m 

OS 1:50,000 map:  114, 115

Summit Height:  313.2m (LIDAR)                                                           

Summit Grid Reference:  SH 58760 61016 (LIDAR) 

Bwlch Height:  288.2m (LIDAR) 

Bwlch Grid Reference:  SH 58906 60906 (LIDAR) 

Drop:  25.0m (LIDAR) 

 

My thanks to Aled Williams for advice relating to the listed name of this hill

Myrddyn Phillips (July 2025) 

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

 

Carreg Gloch (SO 071 621) 

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 Carreg Gloch (SO 071 621)

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 Fforest Glud group of hills, which are situated in the eastern part of South Wales (Region B, Sub-Region B3), and it is positioned with a minor road to its south-west and the A483 road to its west, and has the town of Llandrindod towards the west south-west.

The hill appeared in the original 300m height band of Welsh P30 hills published on Geoff Crowder’s v-g.me website, under the transposed name of Noyadd, with an accompanying note stating; Name from buildings to the South-West.

Noyadd

309m

SO071622

147

200

Name from buildings to the South-West

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, with little consideration for the meaning of the name and where it was appropriately applied to.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose a name of a farm and use it 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

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 127 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 a wood adjoined to the farm of Carreg Gloch in the apportionments, with the details on the Tithe map appearing in the parish of Cefn-llys and in the county named as Radnor. 

Extract from the apportionments

Extract from the apportionments

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Carreg Gloch and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Fforest Glud 

Name:  Carreg Gloch 

Previously Listed Name:  Noyadd 

OS 1:50,000 map:  147

Summit Height:  309.4m (LIDAR)                                                           

Summit Grid Reference:  SO 07151 62163 & SO 07158 62164 (LIDAR) 

Bwlch Height:  260.6m (LIDAR) 

Bwlch Grid Reference:  SO 07468 61943 (LIDAR) 

Drop:  48.9m (LIDAR) 

 

Myrddyn Phillips (April 2025)

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

Castell Cefnllys (SO 088 613) 

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 Castell Cefnllys (SO 088 613)

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 Hirddywel group of hills, which are situated in the northern part of South Wales (Region B, Sub-Region B2), and it is positioned with minor roads to its north north-east, west and south, and the A483 road farther to its west, and has the town of Llandrindod towards the west.

The hill appeared in the original 300m height band of Welsh P30 hills published on Geoff Crowder’s v-g.me website, under the transposed name of Cefnllys Castle, with an accompanying note stating; aka Castle Bank.  The former name appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, whilst the latter appears on the Ordnance Survey 1:25,000 Explorer map.

Cefnllys Castle

304m

SO089614

147

200

Clem/Yeaman. aka Castle Bank

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 Ordnance Survey Draft Surveyors map that prompts the change in the listed name of this hill. 

Extract from the Ordnance Survey 1:25,000 Explorer 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 uses the form of Cefnllys Castell adjacent to the summit of this hill. 

Extract from the Ordnance Survey Draft Surveyors Map

The intricacies of language and prioritising one in favour of another for listing a hill is fraught with complication, with originating Cymraeg names being anglicised and also originating English names being cymricised, examples such as these are more common in border country and especially so for anglicised forms.  There is no steadfast rule that fits all, but as a standard a name that has its origins in the Welsh language and where this is substantiated by either historic documentation and/or contemporary usage should be prioritised in favour of a contemporary anglicised or English version of the name.  Likewise, if a name exists where an element of it is in English and if this name applies to a hill that is situated in a Welsh speaking part of Wales it is standard practice to use a full Welsh term for the name.  It is also standard practice to use a Welsh name for a hill if another name exists that has originated in a different language.

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Castell Cefnllys and this was derived from the Ordnance Survey Draft Surveyors Map, with the language protocol also being used. 

 

The full details for the hill are: 

Group:  Hirddywel 

Name:  Castell Cefnllys 

Previously Listed Name:  Cefnllys Castle 

OS 1:50,000 map:  147

Summit Height:  310.45m (LIDAR)                                                           

Summit Grid Reference:  SO 08841 61344 (LIDAR) 

Bwlch Height:  233.3m (LIDAR) 

Bwlch Grid Reference:  SO 10270 62837 (LIDAR) 

Drop:  77.1m (LIDAR) 

 

My thanks to Aled Williams for advice relating to the listed name of this hill

Myrddyn Phillips (April 2025)