Afon Llynfi (Wye)

A tributary of the River Wye, it runs approximately south to north just to the west of the Black Mountains and partly within the Brecon Beacons National Park.

The river rises as a small stream to the west of the village of Bwlch and flows north for two miles into Llangorse Lake.

The river then travels between the twin villages of Talgarth and Bronllys, forming the boundary of the national park in part.

It then flows northeast past the village of Three Cocks (otherwise known as Aberllynfi) before entering the River Wye just upstream of Glasbury Bridge.

The waters of the Llynfi backed up at Llangors to the point where they overflowed the cols at Pennorth and at Bwlch (both at a height of 189m) and flowed south into the River Usk which was by this time free of ice.