Eleonora Brunacci and Mariano Di Vaio walk the red carpet ahead of the “Racer And The Jailbird (Le Fidele)” screening during the 74th Venice Film Festival at Sala Grande on September 8, 2017 in Venice, Italy. (Photo by Pascal Le Segretain/Getty Images)

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)

A South Korean marine in action during their regular drill on Yeonpyeong Island, South Korea November 1, 2018. (Photo by Jeon Heon-Kyun/Pool via Reuters)

A German rifleman beside the corpse of a French soldier in a trench at Fort Vaux, France, 1916. (Photo by Hulton Archive/Getty Images)

Alvine Uva, right, wrestles the winner's sash from the hands of newly-crowned Miss BumBum 2018 Ellen Santana, left after winning the Miss Bumbum Brazil 2018 pageant in Sao Paulo, Brazil on November 5, 2016. (Photo by Splash News and Pictures)

Fans dressed up in costume await the cast members on the red carpet at the world premiere of the film "The Avengers: Endgame" in Los Angeles, California, April 22, 2019. (Photo by Mario Anzuoni/Reuters)

US rapper Saweetie perform on the catwalk at PrettyLittleThing x Saweetie show Runway, Spring Summer 2020, New York Fashion Week, USA on September 8, 2019. (Photo by Splash News and Pictures)

Lottie Moss attends JULIEN MACDONALD presenting Julien X Gabriela Spring/Summer 2020 fashion show during London Fashion Week at Southwark Cathedral on September 16, 2019 in London, England. (Photo by David M. Benett/Getty Images for Julien Macdonald)