Afon Pyrddin

The Afon Pyrddin is a river forming a short section of the boundary between Powys and Neath Port Talbot in Wales, United Kingdom.

Sgwd Gwladus is formed where a band of erosion-resistant gritstone known as the 'Twelve Foot Sandstone' creates a lip over which the river plunges.

A notable feature above the fall is an erratic block of gritstone which was balanced so that it rocked - at least until Victorian times when it was displaced.

Sgwd Einion Gam, which is a further half mile, upstream can be accessed only by crossing and re-crossing the river itself.

This fall is caused by the presence of a geological fault which brings another hard sandstone known as the 'Farewell Rock' up against softer mudstones.