Although with 10.6 million inhabitants it is by far the most populous region, the Île-de-France also boasts the forests of Fontainebleau, Rambouillet and Compiègne, the châteaux of Versailles and Fontainebleau and the Brie cheese from Seine-et-Marne.
As Paris outgrew 75 (Seine), it had to be sub-divided. The numbers above 91 are the suburbs, or banlieues. In some instances this word retains the connotation of the leafy middle-class outskirts of a city (eg as in Neuilly-Auteuil-Passy, the chic suburbs of Paris). Increasingly, however, the expression is taken to refer to the deprived areas of low-cost housing.
Since French number plates (plaques d'immatriculation) end with the number of the département the driver lives in, you can immediately tell where anyone has come from. Cars bearing Parisian (75) number plates are traditionally disparaged by other drivers if they are seen outside of the capital: Parisians' aggressive driving techniques are legendary.