River Tanat, also known as Afon Tanat, is a river in northern Powys, Wales. Its source is close to the Cyrniau Nod mountain, to the north of Lake Vyrnwy. The river flows in a generally east-south-east direction until it joins the River Vyrnwy near Llansantffraid-ym-Mechain. For a short distance prior to its confluence it flows within western Shropshire, England.[1]
Its tributaries include the Afon Eirth, Afon Rhaeadr, Afon Iwrch and Afon Goch, and they form part of the Tanat Valley.[2]