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 tourist train is decorated with Christmas lights in Bogotá, Colombia on December 10, 2017. (Photo by Jaime Saldarriaga/Reuters)

A robot named “Robovie-II”, developed by Japanese robotics research institution ATR, moves around at a grocery store during a shopping assisting experiment by utilizing the robot in an ubiquitous network technology platform in Kyoto, western Japan January 6, 2010. (Photo by Yuriko Nakao/Reuters)

Boats moored in the middle of Dal lake are silhouetted against the setting sun on January 15, 2018 in Srinagar, the summer capital of Indian administered Kashmir, India. Kashmir, the Muslim majority state, known as the “Paradise on Earth” has for centuries captured the imagination of many writers, poets and film makers and is integral to the tourist trade. Kashmir has been a contested land between nuclear neighbors India and Pakistan since 1947, the year both the countries attained freedom from the British rule. (Photo by Yawar Nazir/Getty Images)

Two visitors look at an artwork “Home Sweet Home: Pandemic Love 1” created by Hong Kong artist Mak Ying Tung at Art Basel in Hong Kong Wednesday, May 19, 2021. Art Basel, one of the world's most prestigious modern and contemporary art exhibitions, is returning to Hong Kong in its ninth edition. The prestige art fair is hosting 104 galleries from 23 countries and territories. (Photo by Vincent Yu/AP Photo)

A performer wearing a face shield looks on during a ceremony held by the Bangkok National Museum to celebrate the return of two ancient relics, believed to have been stolen from Thailand about 60 years ago, from the United States, in Bangkok, Thailand on May 31, 2021. (Photo by Soe Zeya Tun/Reuters)

Wrestlers compete during a traditional Sindhi Malakhra wrestling during a local tournament in Pakistan's port city of Karachi on December 3, 2021. (Photo by Rizwan Tabassum/AFP Photo)

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)