The River Ely is about 24 miles long. Its source lies in the mountains to the south of Tonypandy and it flows out into Cardiff Bay. Its course is very curvy although its course was partially straightened near the Ely Paper Mill. Most of the banks are tree-lined and walking along them you’ll often bump into people fishing. The river is in the heart of many local people and in the summer many children often go paddling in the river