Cambrian Mountains

The Cambrian Mountains (Welsh: 'Mynyddoedd Cambria', in a narrower sense: Elenydd) are a series of mountain ranges in Wales.

Originally the term "Cambrian Mountains" was applied in a general sense to most of upland Wales. Since the 1950s, its application has become increasingly localised to the geographically homogeneous Mid Wales uplands, known in Welsh as the Elenydd, which extend from Pumlumon to Mynydd Mallaen. This barren and sparsely populated 'wilderness' is often referred to as the Desert of Wales. The area includes the sources of the River Severn and River Wye, and was unsuccessfully proposed as a National Park in the 1960s and 1970s. The highest point of the range is Plynlimon, at 2,467 feet (752 m).

The wider, more historic, use of the term also includes Snowdonia in North Wales, and the Brecon Beacons and Black Mountains in South Wales. They range in height up to 3,558 feet (1,084 m) in Snowdonia.

While Snowdonia contains a mix of volcanic rocks and sedimentary rocks of Cambrian and Ordovician age, the mountains of South Wales are mainly Devonian age Old Red Sandstone and Carboniferous Limestone and similarly aged sandstones. The ranges of mid-Wales on the other hand are predominantly formed from Ordovician and Silurian sandstones and mudstones which in many areas outcrop only infrequently so resulting in more rounded grassy hills. The Cambrian Mountains (in the modern sense of the term) are generally less popular with hillwalkers and scramblers than the ranges to their north and south. Since all of Wales' ranges face the predominant westerly air stream coming in from the Atlantic Ocean, they enjoy high levels of rainfall and are the source of numerous rivers, among which the rivers Severn and Wye, which rise on the eastern slopes of Pumlumon, are the largest.

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