Bounce Below Llechwedd Slate Caverns, Blaenau Ffestiniog, LL41 3NB 01248 601 444 Bounce Below Open: See website. Price: See website.

Hats off to whoever thought of this one. Take a vast slate cavern twice the size of St Paul’s Cathedral. Then string giant trampolines and nets across it. Voilà – you have a unique, very topsy-turvy underground experience. Oh, and there’s an underground zip line too.

This off-the-wall new attraction is a world’s first. Be the first kid (or adult) on your block to give it a go.