The Units d'Habitation at Marseilles is a key building of the twentieth century, and a seminal work in Le Corbusier's portfolio. A precursor of buildings in Nantes, Berlin, Breiy en Foret and Firminy, it established, in built form, Le Corbusier's ideas of public housing that had existed only on paper for more than twenty years. David Jenkins argues that the Marseilles Units stands out as a powerful and convincing testament of Le Corbusier's faith in the principles of the Ville Radieuse and the Brutalist medium of rough cast concrete which in other, less able hands, have since been called into question.