A glass skywalk in Wanyuan, Sichuan province, built along the side of a cliff, is the highest such skywalk anywhere in China on January 31, 2017. Some visitors have been proven to be terrified by the experience had to brace against the wall in fear. (Photo by Chinanew.com/AsiaWire)

These frozen caves seem almost otherworldly as they daylight illuminates them. Matej Kriz’s shots reveal the beauty of the brilliant caves, but he’s also very aware of how deadly they can be. The photographer captured the amazing shots in the Vatnajokull National Park on the Breidamerkurjokull glacier tongue. Here: The ice caves, taken in the Vatnajokull National Park in Iceland, on November 11, 2017. (Photo by Matej Kriz/Caters News Agency)

A visiitor bungee jumps during an outdoor festival to celebrate German Unity Day on the 21st anniversary of German reunification on October 3, 2011 in Berlin, Germany. German Unity Day is a national holiday and marks the day West Germany and East Germany were reunited in 1990 following the collapse of the Iron Curtain. (Photo by Adam Berry/Getty Images)

Five-year-old Julian Becker and his 165 pound pet Newfoundland Max have been best buds around all their lives. To commemorate the friendship and to keep Julian's father, a Naval officer who is often away, in the loop, Julian's mom Stasha began taking photos. Photo: Hats off (or on) to Julian for sharing his blanket with his good buddy. Not that the furry beast needs it... (Photo by Stasha Becker/Rex Features)

A man works inside a bakery in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria December 17, 2015. (Photo by Khalil Ashawi/Reuters)

Japanese researchers have sparked hopes of finding a cure for human baldness after successfully growing hair on hairless mice by implanting follicles created from stem cells, Agence France Presse reports. A picture taken on April 13, 2012 and released by the Tsuji Lab Research Institute for Science and Technology of the Tokyo University of Science shows a hairless mouse with black hair on its back at the laboratory in Noda, Chiba Prefecture. (Photo by Tokyo University of Science via AFP)