Ivan Trifonov the world-renowned Austrian daredevil. He holds at least four Guinness World Records, including this one.

Done as a tribute to Jules Verne, author of “Journey To The Center Of the Earth”, Ivan completed one of his daring dreams and became the first person to fly a hot air balloon underground.

Done in the Mamet Cave, in Velebit Mountain, Croatia. OMG this is seriously one on the scariest things we have ever seen