The unusual "Habitat 67" is a residential building built for the 1967 Montreal World's Fair. The plans were initially created as a component of Moshe Safdie's thesis. The complex is made up of around 350 similar prefabricated concrete units, up to 12 storeys tall, each with a different configuration. Safdie's idea was to design a new type of urban housing complex, with units including gardens, retreats and multi-storey interiors.