Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)

A performer poses during celebrations after Rahul Gandhi, newly elected president of India's main opposition Congress party, took charge as the president during a ceremony outside the party's headquarters in New Delhi, India, December 16, 2017. (Photo by Altaf Hussain/Reuters)

Robot inventor Wu Yulu sits on a rickshaw driven by a robot which he invented in his village in rural Beijing's Tongzhou district, China, 17 November 2016. The 54-year-old Chinese farmer living in rural Beijing's Tongzhou district invented 63 robots in the past 30 years. Wu, who only received primary school education, plans to give up the agricultural work for his robot products. He regularly participates in exhibitions, transfers patent rights and teaches at the university to earn money. (Photo by Wu Hong/EPA)

An Indigenous schoolchild dressed in traditional attire takes part in a rally to commemorate Indigenous Resistance Day in Catarina town, Nicaragua October 12, 2016. This holiday coincides with Columbus Day which commemorates Christopher Columbus landing in America in 1492. But rather than celebrating the discovery of the Americas, the Nicaraguans observe Indigenous Resistance Day to celebrate the bravery of the indigenous population in the fight against the Spanish conquistadors. (Photo by Oswaldo Rivas/Reuters)

In this photo taken on February 21, 2017, shooting instructor Kim Su- Ryon poses for a portrait at the Meari Shooting Range in Pyongyang Kim is holding a “Paektusan” target pistol, gifted by late North Korean leader Kim Il- Sung. Visitors to the range can pay 10 USD to shoot ten rounds. (Photo by Ed Jones/AFP Photo)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)

A man dressed as the Sesame Street character Big Bird sits on a bench waiting to take pictures with people walking through Central Park in New York U.S., November 14, 2016. (Photo by Shannon Stapleton/Reuters)

Members of the “Exit Point” amateur rope-jumping group stage a performance as they jump from a 44-metre high (144-ft) waterpipe bridge in the Siberian Taiga area outside Krasnoyarsk, November 3, 2013. Fans of rope-jumping, a kind of extreme sport involving a jump from a high point using an advanced leverage system combining mountaineering and rope safety equipment, marked the end of the group's jumping season and recent Halloween festivities. (Photo by Ilya Naymushin/Reuters)