Topographical Regions, Sub-Regions and Groups

 

Understanding the Welsh Land Mass 

 

Introduction 

From the earliest to the latest, the contents of hill listings have been organised into smaller segments, commonly comprising districts, regions, sections or groups.  Doing so makes it easier to find any individual hill and also breaks up the listing into more manageable units. 

We have opted to use Regions, Sub-Regions and Groups for our split of Wales.  Each follows topography. 

Topography dictates that a land mass is split via watercourses and low points in the terrain, i.e. a col, which is known in Welsh as a bwlch (singular) or bylchau (plural).  If following the course of a river to its source it will be the height and position of the bwlch at near the source that will be the point at which the Group, Sub-Region and Region is formed.  The advantage of using a topographic system to organise a land mass into smaller units is that the natural lay of the land is represented, with each listed hill connected topographically to its parent peak.  This is not the case for listings that split up the land based on man-made structures, such as roads, or administrative boundaries, such as parish or county units. 

 

The complication of Welsh topography 

Wales is an interesting land mass to create topographical Regions, Sub-Regions and Groups from.  Using any relatively large area of land to create sub divisions can be enhanced if they comprise a similar area with a similar amount of hills. However, when creating these sub divisions Welsh topography does present challenges.  A good example of this is the necessity to create a small Sub-Region to accommodate the topographical quirks of the Fforest Glud and Gwaun Ceste groups. 

The bwlch position of Fforest Glud was only confirmed in July 2018 by a detailed survey using a Trimble GeoXH 6000 in conjunction with available LIDAR.  This bwlch is positioned at SO 17776 71803 beside a rail line close to the railway station of Llanbister Road.  This position was confirmed as lower than the alternative bwlch position placed at SN 92601 80035 beside a disused rail line close to the small community of Llangurig. 

The confirmation of this bwlch position meant that Fforest Glud forms a relatively small Sub-Region.  Whereas if the alternate bwlch position was found to be lower in height, the Sub-Region taking in the Fforest Glud and Gwaun Ceste groups would also include the groups of Beacon Hill, Cilfaesty, Hirddywel, Stiperstones, Brown Clee Hill, Worcestershire Beacon and May Hill. 

 

The perils of a geo-topographical system 

Prior to using just topography to form the Regional, Sub-Regional and Group split of Wales, we originally split the country using a combination of geography and topography into three Regions comprising North Wales, Mid & West Wales and South Wales.  As the hill group of Waun Fach is geographically a part of South Wales we listed it as such.  However, topographically this hill group is not joined to the other groups within the old South Wales Sub-Region and along with the group of hills of Ysgyryd Fawr it forms its own small Sub-Region. 

Using a geographical bias also meant that other hill groups were not topographically joined.  An example of this is that we had previously positioned the Craig Berwyn group to appear within a different Sub-Region to the Aran Fawddwy group, having split the Sub-Regions along the Dyfi and Cynllwyd valleys.  This split provided a reasonable geographical symmetry, but violated topographic rules by the fact that Esgairiau Gwynion, Foel Cedig and Carnedd Wen all have Aran Fawddwy as the parent peak and that Craig Berwyn is more closely related to Aran Fawddwy versus Moel Siabod.  We have now rectified these and other anomalies. 

 

Creating Cymru Fawr – Greater Wales 

The topographical land mass of Wales extends eastward beyond its border with England, with its pivotal point found in a field on the outskirts of Market Drayton in Shropshire.  LIDAR analysis conducted independently by both authors gives this point a height of 66.1m positioned at SJ 63688 33945.  This pivotal point can be described as a topographical axis point and is also the critical col for the highest hill in England; Scafell Pike. 

There are very few topographical axis points in the remaining land area of Britain.  Just one other if splitting this overall land mass into three with this being the bwlch of Yr Wyddfa, which is positioned beside the Forth & Clyde Canal in Scotland.  However, the remaining land mass of Britain can be split using more topographical axis points; northern Scotland can be separated via the bealach of Càrn Èite, otherwise reported as Carn Eighe and the south-west of England can be split via the col of High Willhays.  If also using these Britain would comprise five topographical units, all with relatively high drop values and cols under 100m in height. 

We refer to this topographical land area as Cymru Fawr – Greater Wales. 

The topographical axis point of Cymru Fawr - Greater Wales can be shown by imagined water level rise, where the water just skims the singular axis point in the field on the outskirts of Market Drayton.  By doing so the remaining land mass of Cymru Fawr – Greater Wales becomes an island with the unfortunate bi-product of substantial coastal community devastation! 

Taking the water level back to the present day, we can follow the topographical boundary from the axis point in the field just outside of Market Drayton northward following the course of the infant River Duckow to its confluence with the River Weaver and eventual discharge into the River Mersey.   Now back at the axis point we can follow the topographical boundary southward to a part of the Bailey Brook that joins the River Tern, which then joins the Afon Hafren (River Severn) south-east of Shrewsbury (Amwythig) and this now forms the boundary all the way to its culmination in Môr Hafren (Bristol Channel).  This is the course of the defining topographical boundary of Cymru Fawr – Greater Wales. 

 

Wales – Topographical Regions, Sub-Regions and Groups 

Our revised topographical split of Wales comprises two Regions; North Wales and South Wales.  These two Regions are split in to Sub-Regions with North Wales comprising three Sub-Regions and South Wales comprising five Sub-Regions. 

The land area of each Sub-Region follows topography.  The Sub-Regions are then topographically split into Groups.  This topographical system is shared for both Wales as a country and Wales as a land mass. 

Our topographical system was devised through an initial evaluation of the Group level.  We worked on the principle that Groups should complement one another in terms of both the topographical significance and the absolute quantity of hills contained within the group boundaries, give or take reasonable minimum and maximum threshold levels.  By doing this, we formed the basis of the split for Wales with the Sub-Regional split evolving out of our chosen Groups.  This newly devised topographic system has been tested for robustness in relation to listing variations in elevation and prominence. 

We have chosen to use the name of the highest hill in each Group as that for the Group name.  Further research and evaluation may mean that some names are amended in the future. 

We have created manageable Groups of hills based on Topographical Regions and Sub-Regions dictated by watercourses and heights of bylchau.  These hill Groups have been carefully chosen and are divided and numbered from 1 – 52; a group for each week of the year!  When this topographic system is applied to Wales as a country, only two out of the fifty-two Groups are omitted; Brown Clee Hill and Worcestershire Beacon.  The end result is a use of natural occurring features to define units of land that are manageable for hill listing purposes for both Wales as a country and as a land mass. 

 

Aled Williams and Myrddyn Phillips (January 2022)

Sub Region A1 Groups:

1.       Mynydd Twr

2.      Carnedd Llywelyn

3.      Glyder Fawr

4.      Yr Wyddfa

5.      Moel Hebog

6.      Yr Eifl

Sub Region A2 Groups:

7.      Moel Siabod

8.     Moelwyn Mawr

9.      Arenig Fach

10.  Arenig Fawr

11.   Y Llethr

12.  Carnedd y Filiast

13.  Mynydd Hiraethog

14.  Moel y Gamelin

Sub Region A3 Groups:

15.   Raw Head

16.  Craig Berwyn

17.   Foel Cedig

18.  Esgeiriau Gwynion

19.  Aran Fawddwy

20. Cadair Idris

21.  Tarren y Gesail

22. Carnedd Wen

Sub Region B1 Groups:

23. Banc Llechwedd Mawr

24. Pumlumon

25.  Y Garn

26. Carn yr Hyrddod

27.  Mynydd Bach

28. Drygarn Fawr

29. Mynydd Epynt

30. Esgair Wen

31.  Mynydd Mallaen

32. Mynydd Pencarreg

33. Mynydd Preseli

34. Garn Fawr

 

Sub Region B2 Groups:

35.  Hirddywel

36. Cilfaesty

37.  Beacon Hill

38. Stiperstones

39. Brown Clee Hill

40. Worcestershire Beacon

41.  May Hill

Sub Region B3 Groups:

42. Fforest Glud

43. Gwaun Ceste

Sub Region B4 Groups:

44. Waun Fach

45.  Ysgyryd Fawr

Sub Region B5 Groups:

46. Mynydd Sylen

47.  Mynydd Du

48. Penlle’r Castell

49. Fan Fawr

50. Pen y Fan

51.   Cefn yr Ystrad

52.  Craig y Llyn