A competitor gestures as he crawls beneath barbed wire during the Tough Guy event in Perton, central England February 1, 2015. The annual event to raise cash for charity challenges thousands of international competitors in a cross country run followed by an assault course consisting of obstacles including water, fire and tunnels. (Photo by Phil Noble/Reuters)

Peter Weiss, director of the Space Department of COMEX, (c) tests a pressurized suit identical to those used in space expeditions in the lava tunnel of “Caverne Gendarme” on October 12, 2018 in Saint-Philippe, the French overseas island of Reunion. Reunion could become a training site for astronauts. (Photo by Richard Bouhet/AFP Photo)

Workers lay railway track in a tunnel of the Crossrail project in Stepney, east London, Britain, November 16, 2016. Crossrail, which is Europe's largest construction project, is a railway link which will connect outlying areas to the east and west of London with tunnels under the centre of the capital. (Photo by Stefan Wermuth/Reuters)

People wear face masks as they ride an E-scooter in the Old Elbe Tunnel in Hamburg, Germany, Thursday, October 15, 2020. To avoid the spread of the coronavirus the use of a face mask in the 117-year-old tunnel under the Elbe river is mandatory. (Photo by Michael Probst/AP Photo)

Palestinians fleeing Khan Yunis on the coastal road leading to Rafah further south ride on a donkey-cart with their belongings on January 25, 2024, amid continuing battles between Israel and the Palestinian militant group Hamas. Israel pressed its blistering assault on the Gazan city of Khan Yunis on January 25, with the Palestinian Islamist movement Hamas saying dozens were killed in heavy bombardment and urban combat. (Photo by AFP Photo)

Palestinians fleeing Khan Yunis arrive in Rafah with their belongings in a damaged car on February 15, 2024, as battles raged in the sourthern Gaza Strip between Israel and the Palestinian militant group Hamas. (Photo by Mohammed Abed/AFP Photo)

These otherworldly images give a rare glimpse inside caves barely ever seen by the human eye. With its peculiar pools of water and strange colored sediments, the bizarre looking tunnels of the Shakuranskaya cave could be a set straight out of a science fiction film. Found in the disputed region of Abkhazia, around 75 miles outside of Sochi, Russia, it is rumored the incredible underground chambers were formed after a huge earthquake struck the area in 1892. After causing part of a nearby mountain to collapse into the Amtkel River, it is thought the dam-like affect has created a series of interconnecting underground tunnels. Here: a large pool of water inside one of the tunnels. (Photo by Vladimir Mulde/Caters News)

A handout photo made available by the Red Bull Press Office shows Italian pilot Dario Costa in action as he flying through the Catalca Tunnel in Istanbul, Turkey, 04 September 2021. Costa set a new world record for the longest tunnel flown through with an aeroplane marking 1,610 metres. (Photo by Nuri Yilmazer Handout/Rex Features/Shutterstock)