A model poses during the annual World Bodypainting Festival in Poertschach, Austria, July 3, 2015. The event takes place from July 3 to 5 at lake Woerthersee in Austria's southern Carinthia province. (Photo by Heinz-Peter Bader/Reuters)

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)