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)

Gold medalists Kikkan Randall and Jessica Diggins of the United States dancing during the medal ceremony for Cross-Country Skiing – Ladies' Team Sprint Free on day 13 of the PyeongChang 2018 Winter Olympic Games at Medal Plaza on February 22, 2018 in Pyeongchang-gun, South Korea. (Photo by Eric Gaillard/Reuters)

Leicester City hostesses take pictures in front of a billboard as people gather to watch the team's English Premier League soccer match against Everton on a big screen, in Bangkok, Thailand, May 7, 2016. (Photo by Jorge Silva/Reuters)

2016 Rio Olympics, Rhythmic Gymnastics, Preliminary, Group All-Around Qualification, Rotation 1, Rio Olympic Arena, Rio de Janeiro, Brazil on August 20, 2016. Team Brazil (BRA) compete using clubs and hoops. (Photo by Mike Blake/Reuters)

The Washington Wizards dancers strike a pose during the team’s basketball game against the Minnesota Timberwolves at Capital One Arena on November 28, 2022 in Washington, DC. The Wizards won 142-127. (Photo by Geoff Burke/USA Today Sports via Reuters)

M-Sport Ford World Rally Team push their Ford Puma Rally1 Hybrid car to the limits during the fifth round of the Rally Portugal 2023 in Porto on May 14, 2023. (Photo by Paulo Maria/DPPI/Rex Features/Shutterstock)

Klara Bleyer of Team Germany competes in the Artistic Swimming Women's Solo Technical Preliminaries on day one of the Fukuoka 2023 World Aquatics Championships at Marine Messe Fukuoka Hall A on July 14, 2023 in Fukuoka, Japan. (Photo by Marko Djurica/Reuters)

(From front to back) Carson, Rosie and Charlie Surfs Up compete during the World Dog Surfing Championships in Pacifica, California, on August 5, 2023. The event helps local charities raise money by sponsoring a contestant or a team, with a portion of the proceeds going to dog, environmental, and surfing nonprofit organizations. (Photo by Josh Edelson/AFP Photo)