Blea Tarn, Lake District National Park

The walk to Blea Tarn is more rewarding than the tarn itself, which sounds ungracious until you're actually standing there. You'll need to head out from Ambleside towards Great Langdale - the campsites dotted around the valley make it easy to base yourself nearby - and the path climbs steadily through woodland before opening onto moorland proper. The tarn sits in a fold of the fells, unremarkable at first glance: just a dark pool ringed by grass and stone. But catch it on the right day and the reflected peaks turn it into something worth the effort. The walk takes roughly an hour and a half up, depending on your pace and how often you stop to get your breath back. It's not a scramble - a reasonable fell walker manages it without drama - but it's proper climbing, not a stroll. Families with younger kids might find it a bit of a slog for what amounts to a mountain pool with no facilities. The real appeal is for walkers who love the process rather than a destination tick-box: the terrain, the views unfolding as you gain height, the changing light on the Langdale Pikes. If you're camping at Great Langdale Campsite or BaysBrown Farm, it's your obvious afternoon activity. Wet weather renders the path boggy and the tarn loses all magic, so pick a clear day. Go early to avoid the crowds who've read the guidebooks.