Singer Madonna performs during her concert at the AccorHotels Arena in Paris, France, December 9, 2015, on her Rebel Heart Tour. (Photo by Benoit Tessier/Reuters)

A model presents a creation by designers Humberto Leon and Carol Lim as part of their Autumn/Winter 2015/2016 women's ready-to-wear collection for Japanese fashion house Kenzo during Paris Fashion Week March 8, 2015. (Photo by Gonzalo Fuentes/Reuters)

A model presents a creation by French designer Jean Paul Gaultier as part of his Spring/Summer 2015 women's ready-to-wear collection during Paris Fashion Week September 27, 2014. (Photo by Gonzalo Fuentes/Reuters)

Paris Fashion Week, Spring/Summer 2014 Haute Couture collection by Charlie Le Mindu. (Photo by Yoan Valat/EPA)

A passenger without pants waits for the subway train during “The No Pants Subway Ride” in Mexico City January 11, 2015. The event, the fifth organized in Mexico, is an annual flash mob and occurs in different cities around the world, according to its organisers. (Photo by Edgard Garrido/Reuters)

NYC no pants subway ride. Thousands of straphangers took their pants off for the 15th annual "No Pants Subway Ride" hosted by Improv Everywhere. People gathered at seven meeting points throughout the five boroughs at 3PM. All participants met up at Union Square around 5PM to and had a pant-less celebration and the afterparty at Webster Hall. (Photo by Paul Martinka/The New York Post)

The love padlocks, called cadenas d’amour, multiplied until there were thousands of love tokens on the bridge, each engraved with a message of love. (Photo by Charles Platiau/Reuters)

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)