Llyngwyn is a 16 acre spring fed natural lake situated in a secluded area 3 miles east of Rhayader. As long ago as the 12th century this lake was stocked with Carp by the Cistercian Monks from nearby Abbey-Cwm-Hir.
The lake was fished by the Monks on their travels from the Abbey at Strata Florida. The same strain of Carp still exists in the lake today. Fishing for these Carp is allowed in the bay of the lake (from the landing stage to the island).
Llyngwyn is mainly a Rainbow water but there are also some Brown Trout. The lake is stocked regularly with Rainbows upwards of 2 lbs and is a Troutmaster Water, open all the year. Fly fishing only for Trout. There are three rowing boats in the boathouse at the water's edge, which are available from Nantynynach Farm, Nr Llyngwyn for anglers to hire by the day.
The lake varies in depth, from shallow margins to 55 feet at its deepest. There are two sheds available for shelter at the lake and also toilet facilities.