The River Tawe (Welsh: Afon Tawe; ) is a river in South Wales. It flows in a principally southwesterly direction for some from its source below Moel Feity in the Old Red Sandstone hills of the western Brecon Beacons to the Bristol Channel at Swansea. Its main tributaries are the right bank Upper and Lower Clydach Rivers and the Afon Twrch. The total area of the catchment is some 246 km² (95 square miles). The Tawe passes through a number of towns and villages including Ystradgynlais, Ystalyfera, Pontardawe, and Clydach and meets the sea at Swansea Bay below Swansea. The Tawe Valley (Cwm Tawe in Welsh) is more commonly known as the Swansea Valley.