An officer wipes sweat off the face of a Chinese People's Liberation Army (PLA) honor guard soldier as they rehearse for a welcoming ceremony for New Zealand's Governor-General Sir Jerry Mateparae at the Great Hall of the People in Beijing, Tuesday, July 21, 2015. (Photo by Mark Schiefelbein/AP Photo)

It is already one of the world’s most iconic cities, but this incredible collection shows how much Paris has changed over the course of the past century. The collection, by French photographer Julien Knez, shows Paris in the 1940s against a backdrop of how the same places look today. Knez says he put the striking collection together to celebrate the 71st anniversary of the city’s liberation from Nazi control in August 1944. Here: Soldiers outside the Hotel De Ville in the 1940s. (Photo by Julien Knez/Caters News)

A Russian Rosguardia (National Guard) soldier stands at a central avenue in front of a restaurant promoter, a day before Sunday's protest in St. Petersburg, Russia, Saturday, January 30, 2021. (Photo by Dmitri Lovetsky/AP Photo)

Canadian soldiers from the Royal 22nd Regiment take up a position during a non-combative extraction operation in a simulated village as part of Rim of the Pacific (RIMPAC) 2016 exercise held at Camp Pendleton, California United States, July 11, 2016. (Photo by Mike Blake/Reuters)

Indonesian army soldier Partika Subagyo, wearing a costume of the puppet character Bima, dances to raise money for landslide victims, in Solo, December 17, 2014, in this photo taken by Antara Foto. The landslide in Banjarnegara destroyed a village and killed at least 32 people, according to officials. (Photo by Andika Betha/Reuters/Antara Foto)

Several soldiers from the Spanish Air Force observe a Eurofighter EF-2000 fighter aircraft of the Spanish Air Force, as it flies during the Ocean Sky 2023 Military Exercise for advanced air-to-air training in the southern airspace of the Canary Islands, Spain on October 25, 2023. (Photo by Borja Suarez/Reuters)

An Afghan Army soldier secures the hill overlooking the Kart-e Sakhi mosque in Kabul, Afghanistan, Wednesday, March 20, 2013. Thousands of Afghans will celebrate Nowruz on Thursday, March 21, 2013 to mark the first day of spring and the beginning of the year on the Iranian calendar. (Photo by Ahmad Jamshid/AP Photo)

Female soldiers of the self-proclaimed Donetsk People's Republic hold flowers backstage during a beauty pageant to mark International Women's Day in Donetsk, March 7, 2015. (Photo by Marko Djurica/Reuters)