Llyn y Fan Fawr

The walk up to Llyn y Fan Fawr demands proper legs and a decent pair of boots. This glacial lake sits high in the Brecon Beacons, cradled by steep valley sides that look properly dramatic on a clear day - which, granted, you don't always get in mid-Wales. The approach is a genuine hike rather than a gentle stroll: allow a good three hours return, more if you're taking photos at every turn.

What you're actually looking at is a dark, cold mountain lake surrounded by bare stone and grass. It's the kind of place where you understand why old Welsh legends grew up around these peaks - there's something austere about it, a bit lonely even on a busy weekend. Walkers and hikers come here, chiefly. Families with small children will find it hard going, and there's not much to do once you arrive except admire the view and eat a sandwich.

It's free to visit and you can start the walk from the car park near the base of the valley. Early morning or late afternoon light hits the water properly well. Winter's grim but manageable; summer's busy with the proper walking crowd.

If you're camped at Aber Glamping or Brecon Beacons Camping and Caravan Park - both within three miles - this makes a solid half-day expedition. It's the sort of walk that justifies the drive down to this corner of Powys. Not for everyone, but for walkers who like solitude and big landscape, it delivers.