Llyn Cwellyn

The water here is startlingly clear on a calm day, though most visitors find Llyn Cwellyn unremarkable at first glance. It's a proper mountain lake in Gwynedd, roughly five miles south of Caernarfon, ringed by the sort of bare Welsh hills that look dramatic in the right light but can feel a bit bleak when the weather turns.

You can walk round most of the shoreline if you're after a gentle two-hour circuit. There's a car park at the north end and a few spots to fish if you've got a licence - it's stocked with trout. The water's too cold for swimming unless you're the sort who actually enjoys that sort of thing.

Where it earns its place is as a break during a longer day out. If you're staying at Glan Gwna Holiday Park or Rhyd Y Galen Caravan and Camping Park nearby, it's an easy detour rather than a destination in itself. Families with young walkers will manage the paths without drama. The real appeal is the quiet - you won't fight crowds here, which means something in a region that can feel overrun.

Go early on a clear day if you want decent views of Snowdonia beyond. Midweek in shoulder seasons you'll have the place largely to yourself. It's free to visit and you can spend as much or as little time as suits you. Worthwhile if you're in the area, but don't rearrange your whole week around it.