The River Cynon is a river located in South Wales, flowing through the county of Rhondda Cynon Taf. It is approximately 20 kilometers long and is a tributary of the River Taff. The river originates in the Cwm Cynon valley and passes through several towns, including Aberdare and Mountain Ash. The River Cynon is known for its scenic beauty and plays a significant role in the local ecosystem. It supports various wildlife and provides recreational opportunities for residents and visitors. The river is also part of the Cynon Valley, which has a rich industrial history, particularly in coal mining.