Masked youths face off with French police and gendarmes during a demonstration in Paris as part of nationwide protests against plans to reform French labour laws, France, June 14, 2016. (Photo by Willi Effenberger/Pacific Press/SIPA Press)

To an outsider, their passion is at times illegal and often on the verge of life and death. But climbing rooftops of high-rise buildings and exploring abandoned facilities is in the blood of these young Muscovites. The small group calls itself “Rudex”, which stands for “roof and decay exploration”, and is akin a Western youth craze known as urbex or “urban exploration” of man-made structures. Here: Urban explorer Vad Him of Rudex team jumps whilst on a rooftop in Moscow, Russia, August 14, 2017. (Photo by Maxim Shemetov/Reuters)

Members of the London Fire Spinners group meet once a month, pictured at Gabriel's Wharf along the River Thames, UK. A collective of glow and fire performers with extensive performance experience. Dated on March 14, 2025. (Photo by Kevin Jay/Picture Exclusive)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

Oleh Psiuk, frontman of Ukraine's Kalush Orchestra and vocalist Sasha Tab, right, are pictured by a fan before leaving the Universo Hotel, after winning the Grand Final of the Eurovision Song Contest, in Turin, Italy, Sunday, May 15, 2022. (Photo by Luca Bruno/AP Photo)

Robert Price of TREWGrip LLC demonstrates a TREWGrip handheld rear-type keyboard and air mouse for Apple and Android tablets at the “CES: Unveiled”, media preview for International CES, at the Mandalay Bay Convention Center in Las Vegas on January 5, 2014. (Photo by Robyn Beck/AFP Photo)

Scottish actress Karen Gillan (L) and guests attend the Guardians of the Galaxy Vol. 3 World Premiere at the Dolby Theatre in Hollywood, California on April 27, 2023. (Photo by Rich Polk/Getty Images for Disney)