Talybont Reservoir is in the wooded Caerfanell Valley, just south of the village of Talybont-on-Usk in the Brecon Beacons. It was built in the 1930s to supply water for Newport. The minor road running alongside the reservoir crosses the eastern end of the Brecon Becons, emerging at Merthyr Tydfil and on the way passing two more reservoirs, Pentwyn and Pontsticill.