Aygill Caverns

The entrance to Aygill Caverns is genuinely modest - you could walk right past it if you weren't paying attention. A narrow opening in the limestone hillside near Carnforth leads down into a proper underground network, and it's free to explore. The passages are low in places, cramped even, which adds to the slightly illicit thrill of it all. You'll need a torch - bring a decent one, not your phone's pathetic flash.

It's not Cheddar or Show Caves territory here. There are no lights bolted to the walls, no gift shop, no admission fee. What you get instead is the real thing: muddy floors, passages that branch off into darkness, and genuine geological formations. Families with older kids will enjoy it, though anyone under eight might find it claustrophobic. Serious cavers and geologists will be in their element.

You can potter about for an hour or tackle the longer routes that demand proper caving kit if you want to go deeper. The whole area rewards a proper walk - the surrounding moorland is decent enough, and you're well-positioned between Primrose Glamping Pods and Philpin Farm Campsite if you're based on one of the parks. Both are only about five miles away, making this an easy half-day outing.

Bring spare clothes and waterproof kit. The ground stays damp year-round. It's not flashy or polished, but that's precisely why it works.