Ultra- trailers compete at sunrise on September 2, 2017 in Courmayeur, Italy, during the 15 th edition of the Mount Blanc Ultra Trail (UTMB), a 170 km race around the Mont Blanc crossing France, Italy and Switzerland. The 15 th Ultra- Trail du Mont- Blanc (UTMB) is a mountain ultramarathon with numerous passages in high altitude (>2500 m) and in difficult weather conditions (night, wind, cold, rain or snow). (Photo by Jeff Pachoud/AFP Photo)

Tourists gather to watch Mount Agung at Amed beach in Karangasem on Indonesia' s resort island of Bali on November 30, 2017. Thousands of foreign tourists were expected to leave Bali by plane on November 30 following a nearly three- day airport shutdown sparked by a rumbling volcano on the Indonesian holiday island. (Photo by Juni Kriswanto/AFP Photo)

In this timed-exposure night photo taken early on February 12, 2017, Mount Sinabung volcano spews reddish smoke and ash, as seen from the Karo district in North Sumatra province. Activity levels have increased in the past week, with Sinabung shooting hot ash clouds into the sky dozens of times, according to the local volcano monitoring agency. (Photo by AFP Photo/Stringer)

Non-Hindus carry nets as they wait on the edge of the crater to catch offerings cast down by Hindus during the Kasodo ceremony at Mount Bromo, Probolinggo, Indonesia, August 12, 2014. The Kasodo ceremony is a way of Tengger Hindus to express their gratitude to God for good harvest and fortune. The offerings range from vegetables to chickens, from fruits to goats, from money to other valuables. (Photo by Fully Handoko/EPA)

Star trails form over the Memorial House of the Bulgarian Communist Party on mount Buzludzha in this long exposure picture taken on September 12, 2014. The monument was officially opened in 1981 by the Bulgarian Communist regime to mark 100 years of the set up of an organised Socialist movement, a predecessor of the Bulgarian Communist Party. The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized. (Photo by Stoyan Nenov/Reuters)

Frander Arroyo, select wings of butterflies at Blue Morpho Butterfly House in Alajuela, Costa Rica, March 10, 2016. According to Arroyo, owner of Blue Morpho Butterfly House, he collects dead butterflies from his garden to mount as handicraft like earrings, necklaces, paintings and rings for export with prices ranging from $12 to $16 a piece. (Photo by Juan Carlos Ulate/Reuters)

If you’re afraid of heights, caves, the dark, suffer from claustrophobia or vertigo, this might not be for you, but if not, a small Welsh town has the perfect subterranean adventure for you: the world’s largest underground trampoline. Just unveiled in Blaenau Ffestiniog, North Wales, Bounce Below is a network of trampolines and slides mounted to the walls of an abandoned slate mine at heights of 20 feet to 180 feet off the ground. Visitors are welcome to climb, bounce, slide, and jump in the netting amidst a technicolor light show.