It's not exactly a natural wonder, but we'll take it.
At Llechwedd Slate Caverns in Wales, brave souls will soon bounce through a cave on three ginormous trampolines. The huge springboards hang from the walls of a slate cavern -- the highest dangles a frightening 180 feet above the cavern floor. They're bathed in neon light, like an electric underground outer space.
To enter the new attraction, fittingly called Bounce Below, you'll first don a jumpsuit and take a train "inside the mountain" (workers spent five months "labouring in darkness" to carve the cave... no red flags there). Then, jump on any of the three trampolines -- just hop on a 60-foot slide to whoosh from one to the other. When you're done, a spiral staircase leads you out of the cavern to a railroad track. Everything is covered in netting to prevent falls.
Bounce Below opens July 3 -- and we're jumping for joy.
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