Slapton Ley National Nature Reserve

The freshwater lagoon at Slapton stretches for nearly a mile along the Devon coast, separated from the sea by a single shingle ridge - and it's one of Britain's most important wetland sites. You won't find theme park attractions here; what you get instead is serious birdwatching territory, the sort of place where ornithologists spend entire mornings with binoculars glued to their faces.

It's a National Nature Reserve, which means it's protected and managed for wildlife rather than visitors. There are footpaths around the perimeter, and depending on the season you might spot grebes, herons, bitterns, and during winter migrations, all manner of ducks and waders. The shingle beach itself is worth a walk for the views across Start Bay towards Kingsbridge.

Historically, the lagoon was created by natural processes after the last ice age, but it's also a sobering reminder of World War II - American servicemen training for the D-Day landings were killed here in 1944. There's a modest memorial.

If you're staying at Start Bay Caravan and Motorhome Club Campsite just 1.2 miles away, this is practically on your doorstep. It's free to access, though there's no visitor centre or facilities to speak of. Allow a couple of hours for a walk and some viewing. Families with restless kids might find it quiet to the point of tedious, but if you're after a proper nature reserve experience - birdwatchers, keen naturalists, photographers - it's genuinely worthwhile. Wilton Farm Camping South Devon, 4.4 miles off, also makes a decent base for exploring this corner of the coast.