Trampoline parks are sprouting up all across the world. However, they all pale in comparison to Bounce Below - the world's biggest underground trampoline park that opened in the historic slate mining town of Blaenau Ffestiniog in North Wales, on July 3rd. Nestled in a massive cavern that is located inside a 100ft deep and 60ft wide former slate mine, it provides visitors with a bouncing experience like none other                                                                                                                          .                                                                       https://www.dogonews.com/2014/8/20/mining-cavern-transforms-into-worlds-largest-underground-trampoline-park