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. It also forms a part of the boundary of the Brecon Beacons National Park. The river and its waterfalls are one of the key attractions of the Fforest Fawr Geopark, designated in 2005.
The name could mean 'river by the striking fortress' or 'sweet-flowing river'.
The streams of Nant y Bryn, Nant y Fedwen and Nant Hir come together to form the Pyrddin which flows south-eastwards for 3 miles (5 km) to its confluence with the Nedd Fechan.