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)

The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)

Fans attend “The Batman” special screening at BFI IMAX Waterloo on February 23, 2022 in London, England. (Photo by Jeff Spicer/Getty Images for Warner Bros.)

Drone view of vehicles after part of the ceiling collapsed in a mall in Osasco, Brazil on March 9, 2023. (Photo by Carla Carniel/Reuters)

People look out at the city among 30,375 square feet of mirrors at SUMMIT One Vanderbilt in New York on May 22, 2024. The Parade of Ships is seen from SUMMIT One Vanderbilt in NYC as part of the Fleet Week Celebration events. (Photo by Timothy A. Clary/AFP Photo)

Actress Jennifer Aniston is seen filming on location for “The Morning Show” in the Flatiron District on July 28, 2024 in New York City. (Photo by James Devaney/GC Images)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

A folk performer (front R) with make-up and props takes part in a “Blood Shehuo” parade, during a performance in Linyi county, Shanxi province March 21, 2015. “Shehuo” is the common name of Chinese traditional activities consisting of folk performances in northern China. The “Blood Shehuo” performers use make-up and props to re-enact scenes of horror in classic Chinese novels like Water Margin. (Photo by Reuters/Stringer)