A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

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)

Attendants arrive at an inauguration ceremony of a Hello Kitty amusement park in Anji, Zhejiang province November 28, 2014. With an investment of $325 million, Hello Kitty Park will be China's first large scale amusement park scheduled to open to the public on New Year's day. According to state media, there are nearly 60 theme parks being built across China at the moment. (Photo by Carlos Barria/Reuters)

Three Boeing 737 fuselages lie on an embankment on the Clark Fork River after a BNSF Railway Co train derailed Thursday near Rivulet, Montana in this picture taken July 4, 2014. A train derailment in Montana this week damaged a shipment of jetliner fuselages and other large parts on its way to Boeing Co factories in Washington state from Spirit Aerosystems, Boeing said on Saturday. (Photo by Kyle Massick/Reuters)

A general view of Uluru is seen as it rains on November 28, 2013 in Uluru-Kata Tjuta National Park, Australia. Uluru/ Ayers Rock is a large sandstone formation situated in central Australia approximately 335km from Alice Springs. The site and its surrounding area is scared to the Anangu people, the Indigenous people of this area and is visited by over 250,000 people each year. (Photo by Mark Kolbe/Getty Images)

A man being tested for the COVID-19 novel coronavirus reacts as a medical worker takes a swab sample in Wuhan in China's central Hubei province on April 16, 2020. China has largely brought the coronavirus under control within its borders since the outbreak first emerged in the city of Wuhan late last year. (Photo by Hector Retamal/AFP Photo)

Animal rights activists protest in front of the Toennies meatpacking plant and slaughterhouse in Rheda-Wiedenbrueck, Germany, Saturday, June 20, 2020. Hundreds of new coronavirus cases are linked to the large meatpacking plant, officials ordered the closure of the slaughterhouse, as well as isolation and tests for everyone else who had worked at the Toennies site – putting about 7,000 people under quarantiner. (Photo by Friso Gentsch/dpa via AP Photo)

People walk past the sculpture by artist Danger Dave titled “Damien Hirst looking for sharks” at the Swell Sculpture Festival at Currumbin Beach on the Gold Coast, Australia, 17 September 2021. The Swell Sculpture Festival is the largest outdoor art exhibition in Queensland and features 65 large scale contemporary sculptures set along Currumbin Beach. (Photo by Darren England/EPA/EFE)