Around the start of the 20th century, almost half of all Frenchmen depended on the land for their living, and up until World War II, France remained a largely rural country (roughly 25% of the population worked on the land in 1950), but the post-war years also saw an unprecedented move to the cities: only around 4% of the French continue to work in farms and 73% live today in large cities. By far the largest of these is Paris, at 2.1 million inhabitants (11 million in the Parisian region), followed by Lille, Lyon, Marseille (upwards of 1.2 million inhabitants each). Much of this urbanization takes place not in the traditional center of the cities, but in the suburbs (or "banlieues") that surround them (the cement and steel housing projects in these areas are called "cités"). With immigration from poorer countries, these "cités" have been the center of racial and class tensions since the 1960s.