But what was Paris like at the beginning of the 20th century? How did the Paris of the Belle Époque, a timeless capital, slide into a metropolis that was concerned with progress and looking to the future? This is what the Cité de l'architecture offers us to discover in its new exhibition, plunging into the exceptional Albert-Kahn collections to draw a portrait of the city at the time, but also offering a new look at this atypical fund of images. The work of memory presented is the project of Albert Kahn, banker and utopian patron who wanted to preserve a trace of the world. With nearly 5,000 autochromes (first color photos) and 90,000 meters of film, the "Paris" collection of the Archives de la Planète is one of the largest collections devoted to the capital. Today, it takes us back a century: we can see the flooding of the Seine in 1910, the inauguration of the Palais de Chaillot at the 1937 Universal Exhibition, and the exploration of the façades of brothels before they closed. As we leave this immersive walk, the Paris of the 1920s is superimposed on our current Paris, reinventing our relationship with the capital. A magical experience!