Pen y Garreg Dam

The dam itself is a proper feat of Victorian engineering - a curved concrete wall spanning the Elan Valley like someone's drawn a line across the landscape with a ruler. You drive up from Rhayader through increasingly dramatic scenery, and suddenly there it is, holding back an impressive reservoir that reflects the sky like a mirror on calm days.

What strikes you most is the sheer scale of it. The walk along the top takes maybe twenty minutes, and you get views down the valley that genuinely stop you in your tracks. On a windy day, you can feel the weight of the water behind you. It's not a destination that'll keep you occupied for hours - walkers and photography types will get the most from it - but it's absolutely worth the short detour if you're exploring the Elan Valley anyway.

The dam is free to access and you can park nearby without any fuss. Early morning or late afternoon light works best for photos. This area forms part of the Elan Valley water scheme, and the whole valley is worth exploring at a slower pace. If you're staying at one of the nearby parks - Elan Oaks is practically on your doorstep at just two miles away, or Wyeside and The Pines are similarly close - you can easily combine this with walks through the wider valley and visits to the other dams upstream. Bring a windproof jacket; it can get breezy up here even when the valley floor feels calm.