Rhayader is a market town and community in Powys, Wales, within the historic county of Radnorshire. The town is 20 miles (32 km) from the source of the River Wye on Plynlimon, the highest point of the Cambrian Mountains, and is located at the junction of the A470 road and the A44 road 13 miles (21 km) north of Builth Wells and 30 miles (48 km) east of Aberystwyth.