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)

This photo taken on October 8, 2017 shows dancers posing in formation to celebrate the upcoming Party Congress, in Rongan in China' s southern Guangxi region. China will convene its 19 th Party Congress on October 18, state media said, a key meeting held every five years where President Xi Jinping is expected to receive a second term as the ruling Communist Party' s top leader. (Photo by AFP Photo/Stringer)

Haitians pull a car atop a pushcart in Port-au-Prince, October 11, 1994. The price of gasoline has fallen to about $6 US per gallon since U.S. forces occupied Haiti. Before, gasoline had cost as much as $10 U.S. per gallon. (Photo by Eric Draper/AP Photo)

Moruti Mthalane of South Africa is punched by Masayuki Kuroda of Japan during their IBF flyweight title boxing bout in Tokyo on May 13, 2019. (Photo by Charly Triballeau/AFP Photo)

A man walks by as tourists take selfies on the French Riviera city of Nice on June 24, 2019, as temperatures soar to 33 degrees Celsius. Forecasters say Europeans will feel sizzling heat this week with temperatures soaring as high as 40 degrees Celsius (104 degrees Fahrenheit) in an “unprecedented” June heatwave hitting much of Western Europe. (Photo by Valery Hache/AFP Photo)

Flames and smoke rising after a fire that broke out in Izmir province of Aegean Turkey on August 19, 2019. Fire brigade crew continue their works. Forest fires have consumed some 500 hectares (over 1,200 acres) of land in Izmir, Turkeys Aegean coast. On Sunday, the fires broke out in four different regions – including two in the southwestern Mugla province and others in Izmir province, according to Agriculture and Forest Ministry. (Photo by Emin Menguarslan/Anadolu Agency via Getty Images)

People look at the “Dragon de Calais” by Francois Delaroziere and La compagnie La Machine during a rehearsal in the harbour of Calais, France on October 30, 2019. (Photo by Pascal Rossignol/Reuters)

A thirsty timber wolf, Lithuania, 2018. (Photo by Erikas Plucas/Alamy Stock Photo)