Brazilian gymnast Jade Barbosa is seen during a training session at the new Brazilian Artistic Gymnastics Center in Rio de Janeiro January 16, 2015. The Artistic Gymnastics Center is where gymnasts are preparing for the 2016 Olympics. (Photo by Sergio Moraes/Reuters)

Boys play with a drainage culvert used for flood control in Las Pinas, Metro Manila February 28, 2016. (Photo by Erik De Castro/Reuters)

A woman controls a ball on Ipanema beach in Rio de Janeiro, Brazil, April 14, 2016. As hundreds of thousands of tourists begin descending on Rio de Janeiro for the Olympics that start August 5, the headlines have focused on the street violence, the Zika virus, the water pollution and the rush to finish venues and transport. But Rio, known by Brazilians as the “Marvelous City”, glistens despite it all. The beach is a way of life here. (Photo by Nacho Doce/Reuters)

A woman walks with her baby past a PM militarized police soldier in position and aiming his rifle in Rocinha favela in Rio de Janeiro, Brazil on September 23, 2017. Although shooting was reported in the early hours of Saturday in Rocinha – for the seventh day running – officials said that Friday's deployment of 950 soldiers to reinforce police had brought the crisis under control. (Photo by Carl De Souza/AFP Photo)

Men try to get control of a bucking horse a Tradition Day rodeo exhibition during, in San Antonio de Areco, Argentina, Sunday, November 13, 2022. Tradition Day, aimed to preserve gaucho traditions, is celebrated to honor the birth of Argentine writer Jose Hernandez, author of the country's national poem, “The Gaucho Martin Fierro”. (Photo by Natacha Pisarenko/AP Photo)

Revelers dance at a Jacarezinho samba school practice session ahead of Carnival celebrations on February 16, 2014 in Rio de Janeiro, Brazil. The Jacarezinho “favela” was previously controlled by drug traffickers and is now occupied by the city's Police Pacification Unit (UPP). Carnival officially begins February 28, but pre-Carnival celebrations are already underway. (Photo by Mario Tama/Getty Images)

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)

Residents observe a police officer take up position during an operation at the Mare slums complex in Rio de Janeiro March 25, 2014. The federal troops have taken control of security operations in Mare slums complex to help quell a surge in violent crime following attacks by drug traffickers on police posts in three slums on the north side of the city, government officials said. (Photo by Ricardo Moraes/Reuters)