Ajaccio experienced a demographic boom in the 1960s, which explains why 85% of dwellings are post-1949. This is reflected in the layout of the city which is marked by very large areas of low-rise buildings and concrete towers, especially on the heights ("Jardins de l'Empereur") and in the north of the city - e.g. the waterfront, "Les Cannes", and "Les Salines". A dichotomy appears in the landscape between the old city and the imposing modern buildings. Ajaccio gives the image of a city built on two different levels.