The Afon Twrch is a

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

which rises in the Black Mountain 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 forms the boundary between the counties of

Brecknockshire , image_flag= , HQ= Brecon , Government= Brecknockshire County Council (1889-1974) , Origin= Brycheiniog , Status= , Start= 1535 , End= ...

(currently administered as part of the unitary authority of

Powys Powys (; ) is a Local government in Wales#Principal areas, county and Preserved counties of Wales, preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh succession of states, successor state, petty kingdom and princi ...

) and

Carmarthenshire Carmarthenshire ( cy, Sir Gaerfyrddin; or informally ') is a county in the south-west of Wales. The three largest towns are Llanelli, Carmarthen and Ammanford. Carmarthen is the county town and administrative centre. The county is known as ...

and, downstream of Ystradowen, between Brecknockshire and Glamorgan (and unitary authorities of Powys and

Neath Port Talbot Neath Port Talbot ( cy, Castell-nedd Port Talbot) is a Local government in Wales#Principal areas, county borough in the South West Wales, south-west of Wales. Its principal towns are Neath, Port Talbot, Briton Ferry and Pontardawe. The county bor ...

Name

The name derives from

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 ...

afon This is a list of rivers of Wales, organised geographically. It is taken anti-clockwise from the Dee Estuary to the M48 Bridge that separates the estuary of the River Wye from the River Severn. Tributaries are listed down the page in an upstrea ...

/ 'river' and twrch / 'boar'. In common with other rivers sharing the same name, it is believed to refer to the burrowing or snouting action of the waters of the river. The river has also been associated with the legend of

Twrch Trwyth Twrch Trwyth (; also Trwyd, Troynt (MSS.''HK''); Troit (MSS.''C1 D G Q''); or Terit (MSS. ''C2 L'')) is an enchanted wild boar in the ''Matter of Britain'' great story cycle that King Arthur or his men pursued with the aid of Arthur's dog Cavall ( ...

Geography

The headwaters arise on the southern slopes of Bannau Sir Gaer ( Carmarthen Fans) and

Fan Brycheiniog Fan Brycheiniog is the highest peak at a height of (above sea level) in the Black Mountain (''Y Mynydd Du'') region of the Brecon Beacons National Park in southern Wales. There is a trig point at the peak and on the edge of the escarpm ...

and are soon joined by the waters of the Twrch Fechan. The river flows south-west and then south and finally south-east for about 14 km / 9 miles to its

confluence In geography, a confluence (also: ''conflux'') occurs where two or more flowing bodies of water join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main stem); o ...

with the

River Tawe The River Tawe (; cy, Afon Tawe ) is a long river in South Wales. Its headwaters flow initially east from its source below Llyn y Fan Fawr south of Moel Feity in the Black Mountains, the westernmost range of the Brecon Beacons National Pa ...

Ystalyfera Ystalyfera is a former industrial village and community (Wales), community in the upper Swansea Valley, on the River Tawe, about northeast of Swansea. It is an ward (politics), electoral ward and a community (Wales), community in the unitary a ...

. Significant tributaries include the

Nant Gwys The Nant Gwys is a river flowing off the Black Mountain (Y Mynydd Du) in Powys, Wales. Its tributaries Gwys Fawr and the Gwys Fach flow south from Banwen Gwyn and Bwlch y Ddeuwynt respectively and join forces to form the Nant Gwys proper which ...

and the Nant Llynfell.Ordnance Survey Explorer map OL12 'Brecon Beacons National Park: western area' Settlements on the lower section of the river include

Ystradowen Ystradowen is a small village twelve miles west of Cardiff, located in the Vale of Glamorgan in south Wales; its nearest town is Cowbridge which is about three miles to the south. The village was served by Ystradowen railway station between 18 ...

, Cwm-twrch-uchaf, Cwm-twrch-isaf and

Gurnos Gurnos is a community of Merthyr Tydfil County Borough in Wales, United Kingdom. It consists principally of the Gurnos Estate. The population in 2011 5,280. Background The Gurnos Estate is a large housing estate established by Merthyr Tydfil Coun ...

. A

colliery Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from ...

was established at Henllys Vale (OS grid ref SN762137) from which tramroads ran down the valley to Cwm-twrch-isaf. A tall brick chimney is the most impressive of the remains of several buildings associated with the former colliery. A bank of

limekilns Limekilns is a village in Fife, Scotland. It lies on the shore of the Firth of Forth, around south of Dunfermline. History and economy Unlike the neighbouring village of Charlestown, Limekilns is an old settlement dating back to the 14th cen ...

is also located at this spot which can be reached by a half-hour walk along the recently improved line of the tramway or

waggonway Wagonways (also spelt Waggonways), also known as horse-drawn railways and horse-drawn railroad consisted of the horses, equipment and tracks used for hauling wagons, which preceded steam-powered railways. The terms plateway, tramway, dramway ...

running upstream from Brynhenllys Bridge (OS grid ref SN 756125). Parts of

Cwm Twrch Cwm Twrch is a Site of Special Scientific Interest (SSSI) in Carmarthenshire, Wales. SSSI Cwm Twrch SSSI is located on and around the Afon Twrch approximately north-east of Ystradowen, and covers . The site is notable for its geology, where ri ...

on its Carmarthenshire side are designated as an

SSSI A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle of ...

because they expose a good example of a boundary between strata.

References

{{DEFAULTSORT:Twrch Rivers of the Brecon Beacons National Park Rivers of Carmarthenshire Rivers of Neath Port Talbot Rivers of Powys