The River Clydach is a short, steep and fast-flowing river in

Monmouthshire Monmouthshire ( cy, Sir Fynwy) is a county in the south-east of Wales. The name derives from the historic county of the same name; the modern county covers the eastern three-fifths of the historic county. The largest town is Abergavenny, with ...

and the county borough of

Blaenau Gwent Blaenau Gwent (; ) is a county borough in the south-east of Wales. It borders the unitary authority areas of Monmouthshire and Torfaen to the east, Caerphilly to the west and Powys to the north. Its main towns are Abertillery, Brynmawr, Ebbw ...

in south

Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...

. It lies within the

Brecon Beacons National Park The Brecon Beacons National Park ( cy, Parc Cenedlaethol Bannau Brycheiniog) is one of three national parks in Wales, and is centred on the Brecon Beacons range of hills in southern Wales. It includes the Black Mountain (range), Black Mountain ...

. It is around in length. The river rises on the southern slopes of

Mynydd Llangatwg Mynydd Llangatwg or Llangattock Mountain is a hill in the Brecon Beacons National Park in the county of Powys, south Wales. It is named from the village of Llangatwg (or ' Llangattock') which sits in the valley of the River Usk to the north of it. ...

() then heads south-east through Clydach Dingle past

Brynmawr Brynmawr (; , ,) is a market town, community and electoral ward in Blaenau Gwent, Wales. The town, sometimes cited as the highest town in Wales, is situated at above sea level at the head of the South Wales Valleys. It grew with the devel ...

. It then enters the spectacular

Clydach Gorge The Clydach Gorge (also known as Cwm Clydach) is a steep-sided valley in south-east Wales down which the River Clydach flows to the River Usk. It runs for from the vicinity of Brynmawr in Blaenau Gwent eastwards and northeastwards to Gilwern ...

, dropping about to

Gilwern Gilwern is a village within the Brecon Beacons National Park in Monmouthshire, Wales. Historically in Brecknockshire, it extends to either side of the River Clydach, Monmouthshire, River Clydach on the south side of the River Usk, Usk valley. It ...

and its confluence with the

River Usk The River Usk (; cy, Afon Wysg) rises on the northern slopes of the Black Mountain (''y Mynydd Du''), Wales, in the westernmost part of the Brecon Beacons National Park. Initially forming the boundary between Carmarthenshire and Powys, it fl ...

"Clydach" is a common name for watercourses in south Wales and is thought to derive from an old

Welsh Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peop ...

word for "swift" or possibly "stoney", both of which would apply in this case.Owen, H. W., & Morgan, R. (2007). ''Dictionary of the Place-names of Wales''. Gomer Press, Ceredigion.

References

Clydach Clydach Clydach Clydach {{Wales-river-stub