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)

Dominic Bergamin, left, a new Vatican Swiss Guard, is is kissed by his wife Joanne, prior to a swearing-in ceremony, at the Vatican, Wednesday, May 6, 2015. The ceremony is held each May 6 to commemorate the day in 1527 when 147 Swiss Guards died protecting Pope Clement VII during the Sack of Rome. (Photo by Ettore Ferrari/AP Photo/Pool Photo)

The “Yama” (Pit) memorial is seen in the centre of Minsk May 5, 2015. The memorial is dedicated of the destruction of the Minsk ghetto during World War Two, when several hundred thousands of Jews were slaughtered. Belarus will mark Victory Day on May 9, the 70th anniversary of the Soviet Union's victory over Nazi Germany. (Photo by Vasily Fedosenko/Reuters)

A newborn baby pangolin climbs the walls of a cage in Bangkok, Thailand April 20, 2011. The Thai custom office showed 175 pangolins they found hidden in a truck heading into Bangkok. (Photo by Damir Sagolj/Reuters)

These breathtaking images capture the hidden depths of one of the worlds largest caves, which is so big its home to a beach, a river and a jungle. At more than 130m high, and 150m across, the imposing cave is so big as high as the London Eye and wider than one-and-a-half football pitches. Here: The campers set up inside the cave on the beach. (Photo by Lars Krux/Caters News)

An African immigrant tries to jump a fence into a ferry terminal in the western Greek town of Patras April 28, 2015. Afghan, Iranian and Sudanese immigrants, living precariously in abandoned factories in Patras, southwest Greece, try to stow away on nearby ferries to Italy as they seek a better life in Europe beyond crisis-hit Greece. (Photo by Yannis Behrakis/Reuters)

Brazilian farmer Jander Santos de Souza (R) checks his corn plantation which is inundated with floodwaters from the Solimoes River, in the rural municipality of Manacapuru, Amazonas state May 5, 2015. According to the association of farmers in the community, about 70 percent of the agricultural production was lost due to the flooding. (Photo by Bruno Kelly/Reuters)

Russian soldiers are pictured next to the Reichstag building in this undated photo taken May 1945 in Berlin. Some 70 years on from the Battle for Berlin, instrumental in the end of World War II, Reuters photographer Fabrizio Bensch unearthed pictures by Red Army photographer Georgiy Samsonov, showing his portrayal of a city laid siege. Bensch bought an exactly equivalent FED camera, a Soviet copy of the German-made Leica II, choosing to use black and white film to capture images of the self-same locations he detected his way to in modern-day Berlin. (Photo by Georgiy Samsonov/Reuters/MHM)