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 dressed as a bear and wearing a protective face mask amid the outbreak of the coronavirus disease (COVID-19) stands in front of a fountain in central Kyiv, Ukraine on August 11, 2020. (Photo by Valentyn Ogirenko/Reuters)

American singer Dove Cameron arrives for the world premiere of “The Flash” at Ovation Hollywood in Hollywood, California, on June 12, 2023. (Photo by Michael Tran/AFP Photo)

The Christmas tree is lit at Rockefeller Center in the Manhattan borough of New York City, New York, U.S., November 30, 2022. (Photo by Jeenah Moon/Reuters)

Moichara or Bull race is a rural festival where a pair of bulls race each other during the monsoon season. This race is performed by a farmer in Parganas, India on July 4, 2021. (Photo by Sumit Sanyal/SOPA Images/Rex Features/Shutterstock)

A golden lion tamarin monkey holds its newly born baby at a zoo in Jerusalem, Thursday, March 22, 2018. Golden lion tamarins are among the rarest animals in the world, according to the World Wildlife Fund. It is listed as endangered according to the International Union for Conservation of Nature. (Photo by Sebastian Scheiner/AP Photo)

Pitch invader Kinsey Wolanski is taken away by security during the Champions League final soccer match between Tottenham Hotspur and Liverpool at the Wanda Metropolitano Stadium in Madrid, Saturday, June 1, 2019. (Photo by Toby Melville/Reuters)

A woman looks on December 10, 2020 at a metal monolith that has popped up on a riverbank of the Vistula in the Polish capital Warsaw, the latest in a string of similar objects that have recently appeared in Europe and the US. Similar-looking objects were found in the United States, Romania and Britain. (Photo by Wojtek Radwanski/AFP Photo)