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 nude protester faces off against Federal law enforcement officers, deployed under the Trump administration's new executive order to protect federal monuments and buildings, during a protest against racial inequality in Portland, Oregon, U.S. July 18, 2020. (Photo by Nathan Howard/Reuters)

Flower garlands, fruits and a pair of sandals of a woman who died from the coronavirus disease (COVID-19), are placed by her relatives on the spot where she was cremated, as part of a ritual at a crematorium in New Delhi, India, April 30, 2021. (Photo by Adnan Abidi/Reuters)

A group of friends dance the night away at Latitude Festival in Suffolk, United Kingdom on July 22, 2021. Suffolk, returns as a covid test event after a year off due to the pandemic. (Photo by Guy Bell/Alamy Live News)

A woman cools off at a fountain in central Cordoba, southern Spain, 11 August 2021. Andalucia was put on orange alert for high temperatures, with a new heatwave forecast to reach temperatures of over 41 degrees Celsius in the region. (Photo by Salas/EPA/EFE)

A lemur inspects a camera at Tarsus Nature Park in Mersin, Turkey on July 25, 2021. The population of lemurs, one of the inhabitants of Tarsus Nature Park, increases with new births every year. Lemurs are among the most interesting species in the zoo. (Photo by Serkan Avci/Anadolu Agency via Getty Images)

This dyed straw is grown in Ban Dong Saen Suk, Sakon Nakhon province, Thailand on September 28, 2021. Sarawut Intharap, 38, an engineer who capture the image, said: “The straw is entwined together to make mats used for sleeping and eating and they are sold at around £2.50 (3.40 USD) a mat at the local market”. (Photo by Sarawut Intarob/Solent News)

A male sea lion Leo writes the word of tiger in Chinese character at a New Year's attraction to celebrate the Year of the Tiger at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on Monday, January 3, 2022. The calligraphy attraction by the sea lion will be carried through January 31. (Photo by Yoshio Tsunoda/AFLO/Rex Features/Shutterstock)