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 Chimpanzee is seen with funny expressions at Hanover Zoo on September 27, 2013 in Hanover, Germany. (Photo by Barcroft Media)

A participant smiles at the annual Christopher Street Day parade on Kurfuerstendamm in Berlin, Germany, June 27, 2015. (Photo by Fabrizio Bensch/Reuters)

A stroller walks his dogs in an autumnally colored forest in Cuxhaven, nothern Germany on November 7, 2018. (Photo by Patrik Stollarz/AFP Photo)

Cars drive under a rainbow near Bad Langensalza, Germany, Wednesday, November 2, 2016. (Photo by Jens Meyer/AP Photo)

An Extinction Rebellion activist takes part in a protest in Berlin, Germany on October 5, 2020. (Photo by Michele Tantussi/Reuters)

Creative imagery, gold winner: Sprats and Bread, Ruediger Schulz, Germany. (Photo by Ruediger Schulz/2021 Bird Photographer of the Year)

Sheep stand on a dyke as clouds cover the sky over Tossens, northern Germany, on September 2, 2019. (Photo by Mohssen Assanimoghaddam/dpa/AFP Photo)