Geography

Ardaloedd amrywiol a nodedig Mynyddoedd Cambria

The Cambrian Mountains lie between the mountains of Snowdonia in the north of Wales and the Brecon Beacons in the south, inland from the coastline of Ceredigion but west of the central Welsh farmlands.

They can be characterised as a dissected plateau broken only by glacial gouging and by the deep clefts of river valleys: these two processes together have created the landform which exists today. In the south, the upland terrain gradually descends to join the Cothi valley, north of the foothills of the Black Mountains.

The Cambrian Mountains are made up of three distinct upland blocks, from north to south;

Pumlumon – a massif with five peaks, including the highest point Pumlumon Fawr, holding the sources of two major rivers, the Hafren (Severn), and Gwy (Wye) as well as the Rheidol;
The Elenydd – the central range, whose east side runs down into the English speaking areas of central Wales and the Wye Valley whilst the western side slopes off gently into the Welsh-speaking heartlands of Ceredigion. It is the source of the Teifi in addition to several tributaries of the Gwy including the Elan; and
Mynydd Mallaen in the south – with the headwaters of the Tywi (the longest river flowing entirely in Wales). It is an exposed area of unenclosed grazed upland plateau, dominated by heathland and wetland plant communities with bilberry, heather and wet heath mosaic. The plateau drops down into the surrounding valleys through fridd habitats, grassland, rocky scree in places and woodland. The area is Common Land with open access. The plateau is marked by one or two cairns, otherwise it creates a very gentle almost level skyline. There are tracks across the area. There are no trees, nor field boundaries but several rocky outcrops and wet depressions. The area provides extensive views in all directions, and feels extremely exposed, wild, empty and isolated.

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The spectacular gorge and waterfall at Dylife was formed by the deep-cutting headward erosion of the Twymyn-Dyfi to capture the uppermost Clywedog-Severn valley. Similarly, the River Teifi was first diverted by rapid headward erosion of the River Ystwyth along the line of the Ystwyth fault, and then the Ystwyth headwaters in turn were captured by the River Rheidol. The shortened route this provided for the river to the sea from Devils Bridge (10 miles compared with the previous 50 miles to reach the coast at Cardigan) caused the Rheidol to deepen its bed very rapidly, creating the famous waterfall and gorge at Devil’s Bridge.

Upland plateaux

These form the heart of the Cambrian Mountains. The plateau landscapes range from high and irregular peaks and knobs (which rise to 700m and include Pumlumon Fawr) to extensive plateau tops (450-500m) and shallow rolling plateaux (300-500m). These landscapes are typically wild, windswept, remote and covered by rough moorland vegetation. Large areas are only accessible on foot, and the moorlands offer extensive wilderness walks offering distant panoramic views – as far north as Cader Idris in the south of Snowdonia, south to the peaks of Pen Y Fan in the Brecon Beacons, or east to Hay Bluff. On a clear day, it can be possible to see the sea from the westernmost of the Cambrians.

The main peak in the northern part of the range, Pumlumon fawr (752m/2467feet) sits toward the southern end of what is best described as a 10km (6 miles) whaleback ridge, a ridge which never drops below 610m (2000 feet). From the whaleback a series of spurs branch off to east and west separated by valleys. One such spur holds Craig y March at the top of which Owain Glyndŵr is reputed to have celebrated victory following the Battle of Hyddgen in 1401.

Along, or just off, the ridge lie;

four further tops, which alongside “fawr” lead to the name Pumlumon (five peaks, or beacons),
the sources of three major rivers, Hafren/Severn, Gwy/Wye and Rheidol,
a string of Bronze Age funereal cairns,
a long walk, along which you will meet very few people apart from, perhaps, on Pumlumon fawr, and maybe, at the source of the Hafren/Severn. Some of this walk includes a section of “The Cambrian Way”, the long-distance path linking Cardiff to Conwy.

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Plateau margins

The plateau margin landscapes vary from dramatic cliffs and cirques to fragmented hill slopes and saddles. Substantial elevation changes affect the land cover in these areas, which range from windswept upland moor, scree slopes and plantations of sitka spruce at 500m, to enclosed farmland at 150m.

The Dulas Scarp in the north and Pont Marteg cirque on the A44 are highly visible and important landscape features for visitors to the area, but many of the hill slopes and saddles are much more inaccessible.

Narrow valleys

The narrow valleys make up the largest proportion of the area. They cover a wide variety of landforms, from gorges and ravines to U-shaped valleys, but they are all upland stream or river corridors, draining directly from the upper plateaux.

The land cover variation is also great, ranging from moorland to conifer plantations, and inbye pasture to mixed woodland and thick broadleaved woodland.

A number of these valleys have also been flooded to form reservoirs, creating further variety.

See our Waters section for more information about the rivers and reservoirs

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Broad valleys

The broad valleys include wide river corridors and river confluences. They are characterised by flat valley bottoms with enclosed farmland and settlements.

Where roads pass through the region they are generally minor and confined to the valleys, providing the main entry points and access corridors through the area.

Valley sides are steep and historically have been wooded.

Some broadleaved woodlands remain, but many have been cleared for pasture or replaced by coniferous plantations.

Socio-economic status

The area overlaps parts of three unitary authority areas: Powys (50%), Ceredigion (40%) and Carmarthenshire (10%).

17 electoral wards, whose total population in 2001 was around 30,000. The number living within the upland region was around 7,000. To be updated post 2021 census

The predominant land uses are agriculture (~85%) – mainly hill sheep farms – and forestry (~15%).

The remaining small areas are occupied by settlements, reservoirs, quarries, and old mines.