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 woman in costume stands on the street during pre-Halloween weekend party in Shanghai, China on October 28, 2023. During the last weekend before Halloween, which comes on Tuesday, 31 October 2023, hundreds of youngsters dressed in costumes overwhelmed the streets of Shanghai. Halloween in China become popular due to the influences of Western expats and foreign teachers. (Photo by Alex Plavevski/EPA/EFE)

A girl poses in her costume during a Halloween party at a mall in Quezon city, Metro Manila October 24, 2015. (Photo by Ezra Acayan/Reuters)

Participants in costumes pose before a Halloween parade in Kawasaki, south of Tokyo, Japan on October 28, 2018. (Photo by Toru Hanai/Reuters)

A man dressed in a Halloween costume swims along the coast of the northern Lebanese city of Batroun, on October 28, 2021. (Photo by Ibrahim Chalhoub/AFP Photo)

An open house known as “The Doll Asylum” in Portland, Oregon on October 23, 2016. Mark Williams and his wife Heidi Loutzenhiser love halloween so much they fill their home with over 1,000 creepy dolls before opening it up for the public to enjoy over the halloween season. (Photo by ddp USA/Rex Features/Shutterstock)

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

A remote-controlled plane in the form of a witch flies over a neighborhood as the sun sets during Halloween in Encinitas, California, U.S. October 31, 2016. (Photo by Mike Blake/Reuters)