Welcome to the biggest underground trampoline in the world. Actually, if you venture down to Bounce Below, you’ll find not one but three large trampolines housed within a space twice as large (a whopping 300,000 m3, fact fans) as London’s St Paul’s Cathedral. The cavern was dug by hand over 4500 hours, producing 500 tonnes of rubble (don’t worry, those are the last figures I’m going to hit you with).

Bounce Below is in Snowdonia, a beautiful part of Wales that normally lures tourists to its peak attractions, which are significantly higher above sea level than this repurposed slate mine near the town of Blaenau Ffestiniog. Yet if local entrepreneur Sean Taylor has his way, more tourists will abandon the mountains in favour of bouncing some 25 m into the air beneath the ground. It’s all part of his plan to revitalize the mining community and its surroundings, currently suffering from high unemployment.

By creating the ‘most fun place on earth’, full of unique experiences like Bounce Below – not to mention the world’s first four-man zip wire – he hopes to get the region’s economy soaring once again.