A raccoon crawls out of its hiding place on the roof in Berlin, Germany on May 12, 2020. Every evening he leaves his sleeping place to go in search of food. (Photo by Britta Pedersen/dpa-Zentralbild/dpa)

Womentake a selfie in front Russian military vehicles during a rehearsal for the WWII Victory Parade in Moscow on June 17, 2020. Russia's President Putin on June 24 will preside over a massive military parade to mark Soviet victory in World War II, which was postponed due to the coronavirus pandemic. (Photo by Dimitar Dilkoff/AFP Photo)

A participant flies a kite during the “Letatlin N4” annual Festival of Kites, in Moscow, Russia on June 6, 2021. (Photo by Dimitar Dilkoff/AFP Photo)

Medical staff administering the dose of Moderna COVID-19 Vaccine at the M A G Osmani Medical College & Hospital vaccination center in Sylhet, Bangladesh on July 26, 2021. (Photo by Md Rafayat Haque Khan/ZUMA Press Wire/Rex Features/Shutterstock)

Taliban fighter, Mostashhed from Wardak province, looks on as he visits Kabul for the first time as hundreds of Taliban fighters take a day off to visit the amusement park at Kabul's Qargha reservoir, at the outskirts of Kabul, Afghanistan on October 8, 2021. (Photo by Jorge Silva/Reuters)

A woman plays with her three dogs at the beach after sunset in Del Mar, California, USA on November 10, 2017. (Photo by Mike Blake/Reuters)

Two sheep fight in a competition in Zhangjiakou, Hebei province, China on August 1, 2017. (Photo by Reuters/China Stringer Network)

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)