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)

With less than a week before Election Day, a Halloween skeleton holds a vote sign outside a home in Falls Church, Virginia, October 29, 2020. (Photo by Kevin Lamarque/Reuters)

Hundreds of pumpkins lie on a field near Frankfurt, Germany, after sunset on Wednesday, October 16, 2019. The autumn vegetable heralds the approach of halloween. (Photo by Michael Probst/AP Photo)

Mother and son in disguise attend a Halloween celebration at Taipei Children's Amusement Park in Taipei, Taiwan, Sunday, October 29, 2023. (Photo by Chiang Ying-ying/AP Photo)

This photo taken on October 30, 2022 shows people in costumes walking on the street during a celebration ahead of Halloween in Guangzhou in China's southern Guangdong province. (Photo by AFP Photo/China Stringer Network)

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)

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)