Fearless daredevils clamber up the worlds highest man-made climbing wall – running up the face of a 540ft dam. The Diga di Luzzone in Switzerland is considered by climbers as the Everest of wall climbing. (Photo by Ilana Marcus/Caters News)

A man standing on the first cables during the construction of the Golden Gate Bridge with the Presidio and San Francisco in the background, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

Vladimir Putin shows a hold to a young judo wrestler at the Regional Judo Center at the Arena Sports Complex in the Siberian city of Kemerovo on January 24, 2012, during his visit to the region. Putin is known for his passion for judo, in which he has a black belt. (Photo by AFP Photo/STR)

A Buddhist nun walks along a path as a stupa is seen at a temple in Anuradhapura, Sri Lanka October 16, 2016. (Photo by Dinuka Liyanawatte/Reuters)

A woman walks past a stall at a market in Banjul, Gambia December 15, 2016. (Photo by Afolabi Sotunde/Reuters)

A baby Black-crowned Night Heron squawks in its incubator while being cared for at City Wildlife rescue and rehabilitation center in Washington, DC on May 31, 2017. The heron is one of several that have been brought to CW by the staff at The National Zoo over the past few years. (Photo Linda Davidson/The Washington Post)

Men carry a dog, wearing a costume and seated on a stool, as a form of respect as they believe that dogs found water for their ancestors, during a local festival for the Miao ethnic minority in Jianhe county, Guizhou Province, China, August 14, 2016. (Photo by Reuters/China Daily)

A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)