Beacons Reservoir is the top reservoir in the Cwmtaf valley on the river Taff system, the one nearest Brecon, on the A470 between Merthyr Tydfil and Brecon.

This 52 acre water contains wild brown trout and only fly fishing is permitted on a catch and release basis. It has good stocks of free rising fish that respond well to traditional wet and dry fly, average size is about 12oz with pound plus fish often figuring in the catches.