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 riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

Activists and supporters of Ukrainian nationalist groups light flares during a rally to mark the third anniversary of the Euromaidan Revolution in downtown Kiev, Ukraine, 21 November 2016. About one thousand activists took park in the rally during which they burned tires on the Independence Square, destroyed the Russian bank Sberbank and broke windows in the office of a Ukrainian politician Viktor Medvedchuk, according to Ukrainian media. (Photo by Roman Pilipey/EPA)

A protester is taken to hospital after he was wounded by birdshot during a street protest after it was announced that the runoff Jan. 24, presidential election had been postponed, in Port-au-Prince, Haiti, Friday, January 22, 2016. The Provisional Electoral Council in Haiti has postponed the election amid escalating protests by the opposition, which claims the first round was marred by fraud in favor of a government-backed candidate. (Photo by Dieu Nalio Chery/AP Photo)

In this June 23, 2015 photo, Ashaninka Indian beauty contestants pose for a photo with members of a visiting music group, hired to perform during the annual founding anniversary festivities, in Otari Nativo, Pichari, Peru. The contestants wear the simple brown dresses of the Ashaninka woman, their faces dotted in a traditional design with a red dye extracted from a spice called achiote. (Photo by Rodrigo Abd/AP Photo)

A Flemish demonstrator, one of thousands who gathered for a march through Brussels to protest against what the Flemings call their subjucation by the French-speaking Walloons, draws back as he is jeered by a crowd of Walloons on the pavement in a Brussels Street, on October 14, 1962. The Flemish demonstrators clashed with Walloon counter demonstrators as riot police sought to maintain order. The Flemings claim that although they form 60% of the population in Belgium, they are inadequately represented in the government, and they say, the Walloons get most of the top jobs in the armed forces and the diplomatic service. (Photo by AP Photo)

A Palestinian girl wear a face mask during a lockdown imposed following the discovery of coronavirus cases in the Gaza Strip, Thursday, August 27, 2020. On Wednesday Gaza's Hamas rulers extended a full lockdown in the Palestinian enclave for three more days as coronavirus cases climbed after the detection this week of the first community transmissions of the virus in the densely populated, blockaded territory. (Photo by Hatem Moussa/AP Photo)

A woman wearing a protection face mask walks past a mural of a dog in Shanghai, China, 03 September 2020. Daily life in Shanghai is returning to normal while many people still wear protection masks on the street, which are still mandatory in many shopping malls and other public places. (Photo by Alex Plavevski/EPA/EFE)