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 monument with old MiG fighter jet is seen next to a damaged civil infrastructure building at the site of a Russian military strike, as Russia's attack on Ukraine continues, in Vinnytsia, Ukraine on July 14, 2022. (Photo by Valentyn Ogirenko/Reuters)

Caterine Ibarguen of Team Colombia competes in the Women's Triple Jump Qualification on day seven of the Tokyo 2020 Olympic Games at Olympic Stadium on July 30, 2021 in Tokyo, Japan. (Photo by Matthias Hangst/Getty Images)

Brown-throated sloth called “43”, rescued by Juan Carlos Rodriguez and his wife Haydee in a residential area, waits in the kennel getting prepared for being released, at the couple's shelter for sloths, in San Antonio, Venezuela on July 30, 2021. (Photo by Leonardo Fernandez Viloria/Reuters)

Aubrey Zimmermann, 9-months-old, poses for a photo with Santa at the Willow Grove Park Mall ahead of Christmas in Willow Grove, Pennsylvania, U.S. December 3, 2021. (Photo by Hannah Beier/Reuters)

Women take a selfie with a giant dragon lantern decorated near the frozen Houhai Lake in Beijing, Thursday, February 8, 2024. (Photo by Andy Wong/AP Photo)

Sunrise over the River Thames and Tower Bridge in London today morning on January 28, 2024. It has been forecast that Sahara dust will be in the atmosphere. (Photo by Alister Gooding/Picture Exclusive)

Indigenous men perfom the “Danza del Parachicos” (Parachicos dance) to honor the Lord of Esquipulas during a pilgrimage in the municipality of Chiapa de Corzo, Mexico, 15 January 2024. (Photo by Carlos López/EPA)