Haile Sand Fort

A squat brick fort sits marooned on the mudflats near Cleethorpes, looking rather more like an oversized garden shed than a military installation. Haile Sand Fort was built in the 1880s as part of Britain's coastal defence against a French invasion that never quite materialised - one of those Victorian panic projects that ended up outlasting its purpose by about 140 years.

You won't get inside the thing, which is fair enough given it's essentially a crumbling relic accessible only at low tide. The real draw is the walk itself - heading out across the exposed sands from the beach near Cleethorpes gives you that peculiar Lincolnshire coast experience: vast, windswept, occasionally bleak. Kids find it oddly compelling, especially if they're the type who enjoy scrambling over old brick and peering through gun ports. Expect to spend forty minutes to an hour out there, depending on your pace and how much time you waste trying to photograph it at the perfect angle.

Timing matters here. You'll need low tide, so check the tide tables before you head out - getting stuck on the mudflats isn't the disaster it sounds, but it is a bore. The fort itself is free to visit, and it works well as an add-on to a beach day from Haven Cleethorpes Beach Holiday Park up the coast. It's not going to change your life, but it's the sort of peculiar British coastal oddity that makes for decent photos and a decent story back home. Bring proper footwear - the mud can be slippery.