Llangynidr Reservoir

The water at Llangynidr hits you first - that flat, almost glass-like surface surrounded by steep hillsides that feel like they're closing in. It's a proper working reservoir in the Brecon Beacons, north of Crickhowell, built to supply water to the valleys below, and honestly it's a lot more interesting than that description suggests.

You can walk right along the dam itself, which gives you the odd feeling of standing on the edge of something genuinely functional rather than just scenic. The reservoir path takes you around the water with decent views of the surrounding peaks, particularly if you head up onto the slopes - though the terrain gets rough quickly. Most people do the straightforward walk in about forty minutes, which is perfect if you're staying at Cwmdu Campsite six miles away and want an easy morning out.

This isn't a destination in itself. It's a solid pit stop between Crickhowell and the bigger attractions in the Beacons - Pen y Crug or Tablelands if you're doing the full park-hopping thing. Families with young kids find the reservoir walk manageable but potentially dull; it's really walkers and landscape photographers who get the most from it. The autumn light is genuinely special here, and the water can look almost moody when the weather turns.

Free to access, no time restrictions that I'm aware of. The car park is basic but adequate. Go early if you want solitude, because it's a popular local route and weekend mornings can get busy.