The Afon Crawnon is a river in the Brecon Beacons National Park in the county of Powys, Wales. The headwaters rise on the hills north of Trefil and flow northeast down a valley known as Dyffryn Crawnon for 7 km to a confluence with the River Usk just west of Llangynidr.[1] The valley is notable for being at the centre of a major green energy initiative known as The Three Green Valleys project and which involves the construction of several micro-hydro schemes. Dyffryn Crawnon is translated from Welsh to mean "Valley of the Garlic River".
- ^ Ordnance Survey Explorer maps OL12 & OL13 'Brecon Beacons National Park: western area & eastern area'