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 man demonstrates outside Republican presidential candidate Donald Trump's news conference at Trump Tower in New York, U.S., May 31, 2016. (Photo by Shannon Stapleton/Reuters)

A twelve foot long giant hamster has surprised Londoners along the South Bank, Millennium Bridge and Clapham Common on May 26, 2016. A 4-metre pedal-powered mechanical model hamster, which has been created in the likeness of Jaffa the hamster, who is listed as one of the 10 oddest discoveries made by Kwik Fit technicians in customers’ cars. (Photo by Joe Pepler/Rex Features/Shutterstock)

A man is silhouetted as he stands on a walkway in the sky lobby at the Chancellery, the seat of German Chancellor Angela Merkel (not pictured) in Berlin, May 7, 2014. (Photo by Thomas Peter/Reuters)

Back dropped by planet Earth the International Space Station (ISS) is seen from NASA space shuttle Endeavour after the station and shuttle began their post-undocking relative separation May 29, 2011 in space. After 20 years, 25 missions and more than 115 million miles in space, NASA space shuttle Endeavour is on the last leg of its final flight to the International Space Station before being retired and donated to the California Science Center in Los Angeles. Capt. Mark E. Kelly, U.S. Rep. Gabrielle Giffords' (D-AZ) husband, has lead mission STS-134 as it delivered the Express Logistics Carrier-3 (ELC-3) and the Alpha Magnetic Spectrometer (AMS-2) to the International Space Station. (Photo by NASA via Getty Images)

Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

People walk by a car destroyed by a tree which fell during a storm and strong winds, in Limoges, on May 21, 2014. High winds upto 120 km/h and storms have caused at least one death and cut off some 42 000 homes from electricity today in the Midi-Pyrenees region of France. (Photo by Pascal Lachenaud/AFP Photo)

Clowns Perlita and Tapetito, wearing protective gear amid the new coronavirus pandemic, speak with resident Enrique Zeballos as they arrive to disinfect his home free of charge, in El Alto, Bolivia, Friday, September 11, 2020. The lack of traditional employment for the clowns due to the pandemic has led them towards other avenues of making money. But for people with limited income they provide their disinfection services free of charge. (Photo by Juan Karita/AP Photo)