Bounce Below in the Llechwedd Caverns in Wales, U.K., bills itself as the largest underground trampoline. By that it means very large trampolines, constructed of three enormous nets interconnected by spiral stairways and a 60-foot slide within the caverns. Twice the size of London’s St. Paul’s Cathedral, the cavern is outfitted with a spectacular lighting display.
Visitors sign up for a one-hour session of jumping and sliding, appareled in a cotton overall and safety helmet. Children age seven or older and adults are accommodated, although children under 16 years must be supervised by an adult. The attraction opened in July 2014.