Craig Goch Reservoir

The water sits impossibly blue against the grey Welsh hills - Craig Goch Reservoir is one of those places that stops you mid-walk. It's the largest of the Elan Valley reservoirs, built in 1901 to supply Birmingham with drinking water, and the engineering is genuinely impressive if you care about that sort of thing. The dam itself is a proper Victorian piece of work, all stone arches and Victorian swagger.

You can walk right up to it. The circuit takes a couple of hours depending on which way you go, and it's mostly straightforward - no scrambling required. The views across the water to the surrounding moorland are the main event here; it's bleak in the best possible way, especially when the wind picks up and you're practically alone. Walkers will get far more from this than casual visitors - it's not a stroll-round-and-done kind of place. Families with older kids (10+) who actually like walking will find it rewarding; younger ones might struggle with the distance.

It's free to access, and there's parking at the visitor area. Llanidloes is only a few miles south, making this a natural addition to a walking holiday in the Elan Valley. If you're based at Elan Oaks or Wyeside, both close by, this should absolutely be on your list. Go on a clear day if you possibly can - the mist rolls in fast here and half the point is the vista. Allow a solid three hours with breaks, or more if you're the sort who likes to sit and stare at water for a while. Honestly worth the drive.