Blaen-y-Cwm Reservoir

The water here sits proper still on calm days, reflecting the dark slopes of the Brecon Beacons like a mirror someone's just finished polishing. Blaen-y-Cwm Reservoir is tucked into a valley north of Crickhowell, and it's the kind of place you stumble upon rather than plan for - which is exactly why it works so well.

It's a straightforward reservoir, so don't expect fairy-tale ruins or visitor centres with gift shops. What you get instead is a long stretch of water enclosed by steep hillsides, a decent walking route around the perimeter, and genuine quiet. The walk takes roughly an hour depending on your pace and how often you stop to watch the water. Families with kids will manage it fine, though pushchairs are pointless - it's proper footpath.

The best thing about Blaen-y-Cwm is how it sits at the edges of busier Mid Wales. You're close enough to Crickhowell for a cup of tea afterwards, but far enough that most day-trippers miss it entirely. If you're camping at Cwmdu nearby, it's worth the short drive. The light's particularly good in late afternoon when the hills cast long shadows across the water.

There's no entrance fee that I could find, and no facilities to speak of - bring your own refreshments. Go when it's not raining if you can, because there's nowhere to shelter, but honestly even a light drizzle adds to the mood. It's not the most dramatic reservoir in Wales, but that's rather the point.