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)

Gypsies gather at Appleby in Cumbria, United Kingdom on August 12, 2021, for the biggest horse fair of its kind in Europe, which lasts till Sunday. Typically the fair takes place in June, although COVID has pushed it back to August in 2021. In the region of 30,000 people are expected to attend. (Photo by Chris Strickland/Alamy Live News)

A baby baboon appears to ride its mother like a horse at the Chobe River, in The Chobe National Park, Botswana, Southern Africa in January 2023. Young monkeys often ride on their parent's backs, like this Chacma baboon, for protection. (Photo by William Steel/Solent News & Photo Agency)

A security guard tries to separate a boy who hugs India's captain Rohit Sharma, right, after invading the field of play during the second one-day international cricket match between India and New Zealand in Raipur, India, Saturday, January 21, 2023. (Photo by Aijaz Rahi/AP Photo)

A fire-eater performs on the street of China Town during the celebration of Chinese New Year in Manila, Philippines on January 22, 2023. This year is the year of the Rabbit in the Chinese lunar calendar. (Photo by Dante Diosina Jr/Anadolu Agency via Getty Images)

3-year-old Myla Mills plays with a two day old lamb in a toy pram in her family's farmyard in Arley, Worcestershire, United Kingdom on January 28, 2023. Early lambs are produced when the ram is free to tup the ewes over winter. (Photo by Peter Lopeman/Alamy Live News)

Thiago Salgado from the US flips in the air after riding Razzmatazz during Round 3 of the 2023 PBR Unleash the Beast Monster Energy Buck Off at the Madison Square Garden in New York on January 8, 2023. (Photo by Timothy A. Clary/AFP Photo)

One of the Houston Rockets NBA basketball team’s cheerleaders — known as the Power Dancers – in action during a game against the New Orleans Pelicans at Toyota Center on March 19, 2023 in Houston, Texas. The Rockets won 114-112. (Photo by Thomas Shea/Reuters)