Published online by Cambridge University Press: 01 May 2009
In its upper reaches the River Rheidol flows south, parallel to the coast of Cardiganshire, and about ten miles inland. At Devil's Bridge it turns sharply to the west (Text-fig. 1) and enters the sea at Aberystwyth. Due to rejuvenation the river has, in its southward course, incised the floor of its old mature valley the form of which is still clearly visible, and which continues to the south beyond Devil's Bridge to Pontrhyd-y-groes and Tregaron. This part of the valley now contains only small streams.