The Rheidol rises in the headwaters of the Nant y Moch reservoir on the western flanks of Plynlimon and then flows south through the village of Ponterwyd on the main Aberystwyth to Rhayader road.
The Rheidol rises in the headwaters of the Nant y Moch reservoir on the western flanks of Plynlimon near the sources of the Wye and Severn. It then flows south through the village of Ponterwyd on the main Aberystwyth to Rhayader road.