Paris is a round city, comprised of 20 arrondissements or areas. They begin in number in the smallest and oldest section of the city, and spiral outwards to the largest. City maps are arranged and ordered by these arrondissements, starting with the 1er (le premier) in the center at Ile-de-la-Cite and circling to the 20eme (le vingtième). Most street signs indicate their arrondissements under the street name, so it is easy to know where you are. Within each arrondissement are quartiers, or neighborhoods, which have their own charms and customs.
The Seine river runs west-east through the center of the city, splitting it into southern (Left) and northern (Right) banks. Parisians have always divided the city into the Left Bank (Rive Gauche), where historically the universities and artists galleries were located, and the Right Bank (Rive Droite), which is where most of the city’s commerce, banks and large department stores have been located.
Most neighborhoods are a mix of residential and commercial buildings, although certain neighborhoods – such as the 16th – are well known for being leafy and quiet. Therefore there is no ‘main’ business district of Paris, although arrondissements in the center often have quite a few office buildings, and the western suburb of La Défense is very much an office and commercial area. Large parks on the outer edges of the city – the Bois du Boulogne on the western edge and the Bois de Vincennes on the eastern edge – further delineate the urban from the suburban.
The Paris Périphérique is the freeway that encircles Paris and runs in both directions around the city.