Mud-covered tourists pretend to be trapped inside a mud prison at the Daecheon Beach Mud Plaza in the city of Boryeong on South Korea's west coast, July 17, as they take part in the Boryeong Mud Festival, which opened that day and runs through July 26. Boryeong mud is rich in natural mineral component and is considered to prevent skin aging. (Photo by EPA/Yonhap)

The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)

A bear that wandered into a University of Colorado Boulder dorm complex falls from a tree after being tranquilized by Colorado wildlife officials on April 26, 2012. Colorado wildlife official Jennifer Churchill said that the 200-pound male bear was tagged and relocated to a remote Rocky Mountain area. The bear was hit by two cars on May 3 and died. (Photo by Andy Duann)

A Lebanese man carries an injured woman away from the site of a car bomb explosion in a Shiite area and stronghold of the Lebanese militant group Hezbollah at the southern suburb of Beirut, Thursday January 2, 2014. A large explosion has rocked a stronghold of the Shiite Hezbollah group in the southern suburbs of the Lebanese capital. (Photo by Hussein Malla/AP Photo)

A submerged statue of the Hindu Lord Shiva stands amid the flooded waters of river Ganges at Rishikesh in the Himalayan state of Uttarakhand June 17, 2013. Early monsoon rains have swollen the Ganges, India's longest river, swept away houses, killed at least 60 people and left tens of thousands stranded, officials said on June 18, 2013. (Photo by Reuters/Stringer)

Backdropped by a night time view of the Earth and the starry sky, the Space Shuttle Endeavour is seen docked to the International Space Station on May 28, 2011. (Photo by Reuters/NASA)

“Centuries ago, Inuit hunted the bowhead whale. At that time, whale hunting undoubtedly was part of a complex and very important ritual, if only because of the size of the catch. The position that the ancestors of today's Inuit occupied in the living world involved a relationship with the spirit that inhabited each animal but also their species”. (Photo by Robert Frechette/2014 Sony World Photography Awards)

Buildings in Nogales, Mexico (R) are separated by a border fence from Nogales, Arizona, United Sates, October 9, 2016. Building a wall along the U.S.- Mexico border has been a contentious subject in this year's U.S. presidential election. In parts of California and Arizona, a wall already exists. It runs across rocky deserts, flowing sand dunes and miles of agricultural land. (Photo by Mike Blake/Reuters)