Tags: Site Of Special Scientific Interest.
Afon Irfon River Irfon is a river (Afon) in Powys Mid Wales that flows from the upper slopes of Bryn Garw in the Cambrian Mountains through the Abergwesyn Valley past the Nant Irfon National Nature Reserve in the hills above the village of Abergwesyn through Llanwrtyd Wells to its confluence with the River Wye at Builth Wells.
