Devil's Arse (Peak Cavern)

The name alone gets a laugh - Devil's Arse, officially Peak Cavern - and yes, the locals are still amused by it. This is a proper cave system carved into the hillside above Castleton in the Hope Valley, where you descend into cool darkness to see stalactites, underground streams, and chambers that feel genuinely old. The main cavern is vast and theatrical, the sort of place where your voice echoes back at you and the air smells of damp stone and earth.

You'll spend about an hour underground on the standard tour, though it's worth checking current opening times before you drive over - this isn't the kind of attraction that's open every day. The walk down to the entrance isn't steep, but the cavern itself involves some climbing and scrambling, so it's not ideal for very small children or anyone with mobility issues. History buffs will appreciate that the cave's been known since medieval times, and rope-makers actually worked here centuries back - you can still see the ropewalk chamber.

It's free to visit if you go outside the tour times, though you won't see much without proper lighting. The paid guided tour is worth it. If you're camping at Castleton Caravan and Motorhome Club Campsite just down the road, or staying at any of the other sites scattered through the hills, this makes an excellent half-day out when the weather turns damp. Pair it with a walk up Mam Tor or a pint in Castleton village afterwards, and you've got a proper Derbyshire afternoon sorted.