Craig Goch Dam

The dam itself is a proper engineering marvel - all pale stone and clean lines stretching across the valley like someone's drawn a ruler across the landscape. Craig Goch is the largest of the four dams in the Elan Valley, built in 1901 to supply water to Birmingham, and it remains one of the finest examples of Victorian engineering you'll clap eyes on in Wales. You can walk across the top, which gives you a genuine sense of scale, and the views down the valley are genuinely worth the trip.

Walkers will get the most from this place. The walk across the dam takes maybe ten minutes, but the surrounding Elan Valley offers proper hiking territory - you can do longer loops that take you past the other dams (Penygarreg and Garreg-ddu) if you're feeling ambitious. The water level fluctuates depending on the season, which changes how the whole thing looks, so it's not quite the same twice. On a clear day, the views stretch for miles. Rain, though, and it can feel a bit bleak.

Rhayader is your nearest town, just a few miles south, and if you're staying at Elan Oaks or Wyeside - both solid caravan parks within easy striking distance - you've got a cracking half-day activity. Neither kids nor non-walkers will find much to do once they've crossed the dam and taken the photos, so factor that in. Free to visit and accessible year-round, though winter can be muddy. Allow a couple of hours if you're doing the longer valley walk.