The River Afan is a river in Wales whose river valley formed the territory of the medieval Lords of Afan. The Afan Valley encompasses the upper reaches of the river. The valley is traversed by the A4107 Afan Valley Road. Settlements in the area include Cwmafan, Pwll-y-glaw and Cymmer. The town of Aberavon grew up on the banks of the river, and was later subsumed by the larger centre of population known as Port Talbot. The political constituency still retains the name Aberavon (aber meaning mouth of a river).