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)

These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

Emperor penguins gathered together to keep their chicks warm in these pictures. Marine scientist Frederique Oliver snapped the protective parents in Antarctica as they huddled against the huge winds.The adorable birds have to battle temperatures on -20 degrees Celsius as well as winds of up to 40 knots on the ice. (Photo by Frederique Oliver/Caters News)

Winner Petra Vlhova from Slovakia celebrates on the podium of the FIS women's World Cup slalom in Zagreb, the “Snow Queen Trophy 2022”, on January 4, 2022. (Photo by Antonio Bronic/Reuters)

Brazilian model Alessandra Ambrosio arrives at the pier of the Excelsior Hotel on August 31, 2022, on the opening day of the 79th Venice International Film Festival at Lido di Venezia in Venice, Italy. (Photo by Tiziana Fabi/AFP Photo)

A model dressed in clothes made of waste products such as plastic bags, plaster nets, rope, paper and calendar leaves poses for a photo at a recycling facility in Diyarbakir, Turkiye on March 25, 2024. (Photo by Bestami Bodruk/Anadolu via Getty Images)

A bar girl shows off her sexual desires along the Walking Street where bars and sеx scenes are a commonplace July 31, 2016 in Pattaya, Thailand. Thailand's first female minister of tourism would like the sеx trade that is a huge business in the country to be banned. Tourists flock to Thailand for many sights including beautiful beaches but also for sеx tourism. Cities like Bangkok and Pattaya are well known as hubs of the Southeast Asian sеx trade, despite the fact that prostitution has been illegal in Thailand since 1960. (Photo by Paula Bronstein/Getty Images)

A woman talks on her cellphone as she walks around Tajrish commercial district without wearing the mandatory Islamic headscarf in northern Tehran, Iran, Saturday, April 29, 2023. More women are choosing not to wear the mandatory headscarf, or the hijab, publicly in Iran. Such open defiance of the law follows months of protests over the September death of 22-year-old Mahsa Amini while in the custody of the country's morality police, for wearing her hijab too loosely. (Photo by Vahid Salemi/AP Photo)