Opposition protesters take to the streets of Moscow. Mass meeting in Bolotnaya Square on December 10, 2011 in Moscow, Russia.

Photo by: Stas Sedov and Dmitry Chistoprudov; Source: AirPano

Boys dressed in historical uniforms stand before a military parade in Red Square in Moscow November 7, 2014. The parade marked the anniversary of the 1941 parade when Soviet soldiers marched through the Red Square towards the front lines of World War Two. (Photo by Maxim Shemetov/Reuters)

Police officers detain a woman during an unsanctioned rally in the center of Moscow, Russia, Saturday, July 27, 2019. Russian police are wrestling with demonstrators and have arrested hundreds in central Moscow during a protest demanding that opposition candidates be allowed to run for the Moscow city council. (Photo by Pavel Golovkin/AP Photo)

Demonstrators take part in a mass anti-Putin rally on December, 24, 2011 in Moscow, Russia. Tens of thousands of demonstrators rallied in cities across Russia to protest alleged vote fraud in recent parliamentary elections and to express their discontent with Prime Minister Vladimir Putin, leader of the dominant United Russia party. (Photo by Alexander Aleshkin/Epsilon/Getty Images)

Photo by: Rustem Adagamov; Source: LiveJournal

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)

Parent hedgehogs Maria, left, and Gosha, 2nd right, eat with their albino babies in a private Zoo in Moscow, Russia, Thursday, August 22, 2013. Three rare albino hedgehog babies, born on the same day as Britain's new prince, have moved into a miniature castle at a Moscow petting zoo. The three are named after the Prince of Cambridge – George, Alexander and Louis. On Thursday, when they turned one month old, they were shown their new home at the All-Russia Exhibition Center. (Photo by Alexander Zemlianichenko Jr./AP Photo)

An alert-looking Maine Coon during the Grand Prix Royal Canin cat exhibition in Moscow, Russia on December 4, 2016. The breed’s origin is unknown, but one legend claims it is descended from cats brought to the US by an English seafarer called Captain Coon. (Photo by Dmitry Serebryakov/TASS)

Women take pictures by a vintage car during the 2019 GUM Motor Rally featuring classic cars in Moscow, Russia on July 28, 2019. The youngest car at this year’s rally is 35, the oldest – a GAZ-A convertible – is 85. (Photo by Artyom Geodakyan/TASS via Getty Images)