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)

Sun Rongchun, 57, exercises with an improvised cervical traction device attached to a high bar at a sports complex in Shenyang, Liaoning province, China on April 9, 2019. (Photo by Sheng Li/Reuters)

A girl in an angel costume walks with her family past vegetable vendors in Havana, Cuba, Wednesday, April 10, 2019. (Photo by Ramon Espinosa/AP Photo)

People take part in a gay pride parade in Warsaw, Poland, on Saturday, June 8, 2019. The Equality Parade is the largest gay pride parade in central and Eastern Europe. It brought thousands of people to the streets of Warsaw at a time when the LGBT rights movement in Poland is targeted by hate speeches and a government campaign depicting it as a threat to families and society. (Photo by Czarek Sokolowski/AP Photo)

Chile's Mary Dee Vargas (L) reacts after defeating Brazil's Larissa Farias compete in their Judo Women's –48 kg Bronze Medal contest during the Lima 2019 Pan-American Games in Lima on August 8, 2019. (Photo by Guadalupe Pardo/Reuters)

A villager harvests water chestnuts in Feijiadai Village, Zhejiang Province, China on September 20, 2019. (Photo by Huang Zongzhi/Xinhua News Agency/Barcroft Media)

Navy midshipmen celebrate a Navy touchdown during the second half of an NCAA college football game, Saturday, December 14, 2019, in Philadelphia. Navy won 31-7. (Photo by Jonathan Newton/The Washington Post)

Poland's Piotr Lisek celebrates after winning in the Men's pole vault during the IAAF Diamond League competition on July 12, 2019 in Monaco. (Photo by Eric Gaillard/Reuters)