The River Cynon () in

South Wales South Wales ( ) is a Regions of Wales, loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the Historic counties of Wales, historic counties of Glamorgan and Monmouthshire ( ...

is a main tributary of the Taff. Its source is the rising of Llygad Cynon (OS grid ref SN 95240 07740) at above sea level at

Penderyn, Rhondda Cynon Taf Penderyn () is a rural village in the Cynon Valley, Rhondda Cynon Taf, Wales, located near Hirwaun. Location The village lies on the A4059 road between Hirwaun and Brecon and is the last settlement on that road in the county of Rhondda Cynon ...

and flows roughly southeast, into the Taff at

Abercynon Abercynon () is a village and community (Wales), community (and electoral ward) in the Cynon Valley within the unitary authority of Rhondda Cynon Taf, Wales. The community comprises the village and the districts of Carnetown and Grovers Field to ...

in the same district. The water emerging at Llygad Cynon has been traced back to the

sink A sink (also known as ''basin'' in the UK) is a bowl-shaped plumbing fixture for washing hands, dishwashing, and other purposes. Sinks have a tap (faucet) that supplies hot and cold water and may include a spray feature to be used for fas ...

of the Nant Cadlan at Ogof Fawr.

Course

The Nant Cadlan and its tributary the Ceunant Du rise on the slopes of Cefn Cadlan to the northeast of Penderyn flowing initially southeast and then south on the east side of the village to the point where the Cynon arises, adding to the flow emerging from the rising. The waters of the Nant y Bwllfa enter the Cynon as a left-bank tributary between Penderyn and

Hirwaun Hirwaun (, ; ) is a village and Community (Wales), community at the north end of the Cynon Valley in the County Borough of Rhondda Cynon Taf, South Wales. It is NW of the town of Aberdare, and comes under the Aberdare post town. At the United Ki ...

. Downstream, the course of the river has been altered at the former Hirwaun Ironworks. The combined flow of the Nant Hir and Nant Melyn enter the river to the north of

Penywaun Penywaun (also in ) is a community, electoral ward and north-western suburb of Aberdare in the Cynon Valley within the county borough of Rhondda Cynon Taf, Wales. At the 2011 census, the population of the ward was registered as 3,063. Etymology ...

and that of the Nant y Gwyddel to the east of Penywaun. The Dare River enters as a right bank tributary at

Aberdare Aberdare ( ; ) is a town in the Cynon Valley area of Rhondda Cynon Taf, Wales, at the confluence of the Rivers Dare (Dâr) and River Cynon, Cynon. Aberdare has a population of 39,550 (mid-2017 estimate). Aberdare is south-west of Merthyr Tydf ...

and the Aman River at

Aberaman Aberaman is a village near Aberdare in the county borough of Rhondda Cynon Taf, south Wales. It was heavily dependent on the coal industry and the population, as a result, grew rapidly in the late nineteenth century. Most of the industry has now ...

. The final tributary of any size is the Nant Pennar which enters on the Cynon's left bank at

Mountain Ash Mountain ash may refer to: * ''Eucalyptus regnans'', the tallest of all flowering plants, native to Australia * Mountain-ashes or rowans, varieties of trees and shrubs in the genus ''Sorbus'' See also

* Mountain Ash, Rhondda Cynon Taf, a town ...

(Welsh: Aberpennar).

Hydronymy

The name is recorded as ''Canan'' in 1253 and ''Kenon'' in 1536-9, with the final vowel pronounced with an ə sound. While Thomas Morgan stated that the name was a compound of the elements "cyn" (meaning chief) and "ain" (water or brook), giving a meaning of the "chief brook", modern writers more commonly state that the river derives from a personal name, Cynan or Cynon. This is also the preferred derivation for the ''Ffrwd Cynon'', a tributary of the

Teifi The River Teifi ( ; , ), formerly anglicised as Tivy, forms the boundary for most of its length between the Welsh counties of Ceredigion and Carmarthenshire, and for the final of its total length of , the boundary between Ceredigion and Pembr ...

. However, no

eponym An eponym is a noun after which or for which someone or something is, or is believed to be, named. Adjectives derived from the word ''eponym'' include ''eponymous'' and ''eponymic''. Eponyms are commonly used for time periods, places, innovati ...

has been identified for either river.

Related terms

Together with two neighbouring rivers, it gives its name to a local authority, with unitary status,

Rhondda Cynon Taf Rhondda Cynon Taf (; RCT; also spelt as Rhondda Cynon Taff) is a Principal areas of Wales, county borough in the South East Wales, south-east of Wales. It consists of five valleys: the Rhondda Fawr, Rhondda Fach, Cynon, Taff () and Ely valleys, ...

. The valley, broadly defined as the bulk of the

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

is detailed in

Cynon Valley Cynon Valley () is a former coal mining valley in Wales. It lies between Rhondda and the Merthyr Valley and takes its name from the River Cynon. Aberdare is located in the north of the valley and Mountain Ash in the south. From 1974 to 19 ...

References

Brecon Beacons Fforest Fawr Rivers of Rhondda Cynon Taf Rivers of the Brecon Beacons National Park {{Wales-river-stub