The article analyzes how some non-fiction films (institutional documentaries, newsreels, and amateur films) produced between 1945 and the late 1950s in France are featured as archive images in contemporary documentaries on the post-WWII era. These post-war non-fiction films depict the challenging reconstruction of cities that had been heavily damaged during the end of the war. Meanwhile, the uniqueness of this architectural heritage seems to have been forgotten despite the inventiveness of the modern architecture of the 1940s and 1950s. The recent decades have even witnessed a net outflow of inhabitants from the rebuilt city centers. By promoting this architectural heritage, cinema plays a key role in reconnecting the inhabitants with the history that shaped the local identity of these rebuilt cities, such as Dunkirk or Lorient. Indeed, documentaries produced on the singular living experiences like the Unité d'Habitation designed by Le Corbusier in Marseille or the Cités Castors ("Beavers" cities) built by and for their inhabitants allow these small communities to share a sense of belonging and to maintain a collective identity. Besides, the digitization and the re-use of amateur films allow us to rediscover everyday life during the post-war reconstruction.