Gwyddior keeps company with Coch Hwyad in the hills above Llanbrynmair, part of the same small association's modest patch of upland water in the headwaters of the Twymyn. Wild brown trout, unstocked, largely unbothered by anglers from outside the valley — this is about as far from a marketed fishery as Welsh stillwater fishing gets. There's a directness to it that's easy to like: no boats, no elaborate rules, just a lake in the hills and a club that keeps things simple. Worth the effort of tracking down permission if you're already in Llanbrynmair country working the Twymyn or its neighbours, and want a stillwater detour without the usual trimmings.

• Lake
• Silurian mudstone shale