This computer image provided Monday March 17, 2014 by the Press Office of socialist candidate to Paris Mayor Anne Hidalgo, shows a tunnel of abandoned railway from the 19th century, now ramshackle and overgrown, turned into a cinema. Hidalgo’s plan envisions not just a green space but in the tunnels, places for farming fish and mushrooms. (Photo by AP Photo/Anne Hidalgo's Press Office)

A protester dressed as a clown holds an umbrella over a Swiss police officer on a motorbike during a May Day demonstration in Zurich, Switzerland on May 1, 2017. (Photo by Arnd Wiegmann/Reuters)

The Swiss Federal Palace (Bundeshaus) is illuminated by giant light projection "The Jewel of the Mountains" in Bern, Switzerland October 15, 2015. The light and sound show will run every evening until November 29, 2015. (Photo by Ruben Sprich/Reuters)

A donkey carrying sacks of coal walks through the narrow tunnels of a coal mine, in Choa Saidan Shah in Punjab province April 29, 2014. Coal miners in Chao Saidan Shah use donkeys to transport coal from the depths of the mines to the surface. (Photo by Sara Farid/Reuters)

Local villagers ride a local coal powered steam train on March 27, 2015 at a station in the town of Shixi , Sichuan Province, in Southern China. While China boasts the world's most extensive high-speed rail infrastructure with over 16,000 kilometers of track, the Shixi-Bagou railway is still a primary connection for local villagers between towns and is kept alive by tourist cars carrying passengers for ten times the price. The rail line came into service in the late 1950s and the train was initially used to transport coal from a now-shuttered mine before passenger carriages were added. (Photo by Kevin Frayer/Getty Images)

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)

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)

Henry Leese drives a 1952 British Rail Ivatt number 46512 at Strathspey Steam Railway on August 27, 2013 in Aviemore,Scotland. This year marks the 150th anniversary of the Highland Main Line built as a transportation link to the South for lairds and landowners living in northern Scotland. (Photo by Jeff J. Mitchell)