Banwen is a small village in Neath Port Talbot county borough (NPT) in Wales. Banwen is part of the community of Onllwyn along with the village of Onllwyn itself and the adjacent parish of Dyffryn Cellwen. Banwen is in the Upper Dulais Valley, with views over the southern slopes of the Brecon Beacons (Welsh: Bannau Brycheiniog). Banwen consists of a single street named Roman Road.