A member of the “Castellers Minyons de Terrassa” adjusts her belt before forming a human tower or ÒcastellÓ during the festival of the patron saint of Barcelona “The Virgin of Mercy” at Sant Jaume square in Barcelona, Spain, September 20, 2015. The formation of human towers is a tradition in Catalonia dating back to the 18th century. (Photo by Susana Vera/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)

A man rides a horse through flames during the annual “Luminarias” celebration on the eve of Saint Anthony's day, Spain's patron saint of animals, in the village of San Bartolome de Pinares, northwest of Madrid, Spain, January 16, 2017. (Photo by Paul Hanna/Reuters)

Iraqi soldiers from 9th Armoured Division give drops of water to a dehydrated child rescued earlier by soldiers at the frontline, during the ongoing fighting between Iraqi forces and Islamic State militants near the Old City in western Mosul, Iraq June 13, 2017. (Photo by Erik De Castro/Reuters)

Waiters pose at their terrace of their restaurant rue de Buci in Paris on June 2, 2020, as cafes and restaurants reopen in France, while the country eases lockdown measures taken to curb the spread of the COVID-19 (the novel coronavirus). (Photo by Martin Bureau/AFP Photo)

Police officers look on as they stand guard to secure the area where Dutch celebrity crime reporter Peter R. de Vries, known for his reporting on some of the most renowned criminals in the Netherlands, was reportedly shot and seriously injured, in Amsterdam, Netherlands, July 6, 2021. (Photo by Eva Plevier/Reuters)

ABC's “Dancing with the Stars”, Season 30 stars American Latin and ballroom dancer and choreographer Jenna Johnson (L) and American dancer, singer, actress, and YouTube personality JoJo Siwa on September 17, 2021. (Maarten de Boer/ABC via Getty Images)

A Hindu devotee ululates as she holds a banana tree trunk after taking a dip in the waters of the Ganges river during a ritual as part of the Durga Puja festival in Kolkata, India, September 27, 2017. (Photo by Rupak De Chowdhuri/Reuters)