Stunning silhouettes under European cities reveal the size and splendor of the continent’s urban foundations. Photographer and content-manager Anna Arinova, 28, from Moscow, captured the awe-inspiring labyrinths in Russia and Germany. Here: Regenwurmlager, Poland. The Regenwurmlager is an extensive underground fortification area constructed by Germany in 1920s-1940s, now in western Poland, near the city of Międzyrzecz. (Photo by Anna Arinova/Caters News)

A ship builder walks past a section of the Oasis Class 3 cruise ship at the STX Les Chantiers de l'Atlantique shipyard site in Saint-Nazaire, western France, February 17, 2015. The Oasis-class III vessel is scheduled for delivery in mid-2016. (Photo by Stephane Mahe/Reuters)

A woman takes pictures with her mobile phone at a building, which is made by half of a replica of the Qinian Hall of the Temple of the Heaven (R) and half of a western building, at a studio for productions of films and television shows on the outskirts of Shijiazhuang, Hebei province, China, December 3, 2015. (Photo by Reuters/Stringer)

A Turkana boy herds cows as he carries a rifle in north western Kenya near the town of Kibish inside the Turkana region of the Ilemy Triangle September 26, 2014. The Turkana people have historically clashed over ethnic differences and precious resources such as fishing, pasture and fresh water with other tribes bordering their territory, such as the Dassanach from southern Ethiopia. (Photo by Goran Tomasevic/Reuters)

A member of a local swimming club holds a Russian national flag as he dives in at the start of a 24-hour swimming marathon near the western Siberian city of Barnaul March 29, 2014. Thirty members of the club will swim in turn during the event, held to mark Crimea becoming part of Russia, local media reported. (Photo by Andrei Kasprishin/Reuters)

A Tibetan man stands nearby as a young tourist poses for photos on a white yak at the shore of the lake in Namtso in western China’s Tibet Autonomous Region, as seen during a government organized visit for foreign journalists, Wednesday, June 2, 2021. (Photo by Mark Schiefelbein/AP Photo)

People wade through a road flooded by heavy rain in Kurume, Fukuoka prefecture, western Japan, Saturday, August 14, 2021. Torrential rain pounding southwestern Japan triggered a mudslide early Friday that swallowed some people and was threatening to cause flooding and more landslides in the region. (Photo by Kyodo News via AP Photo)

Participants celebrate the awakening of the Hoppeditz, a fictional character whose return to life marks the start of the carnival season in Düsseldorf, western Germany on November 11, 2021. The 11.11. is celebrated this year again under Corona conditions in presence. However, in the carnival strongholds of Cologne and Düsseldorf, this only applies to the vaccinated and the recovered. (Photo by Federico Gambarini/dpa/Alamy Live News)