¹ French Land Register data, which exclude lakes, ponds, and glaciers larger than 1 km² (0.386 sq. mi. or 247 acres) as well as the estuaries of rivers.
The city of Paris is divided into 20 arrondissements municipaux, more simply referred to as arrondissements (pronounced /əˈɹɒndɨsmənt/ in English and /aʁɔ̃dismɑ̃/ in French). These are not to be confused with departmental arrondissements, which subdivide the 100 French départements. The word "arrondissement", when applied to Paris, refers almost always to the municipal arrondissements listed below. The number of the arrondissement is indicated by the last two digits in Parisian postal codes (75001 up to 75020).
The 20 arrondissements are arranged in the form of a clockwisespiral, starting with the 1st in the middle of the city on the right bank (north bank) of the Seine River. The French cities of Lyon and Marseille are also subdivided in this way.
Notes:
1. With the Bois de Vincennes
2. Without the Bois de Vincennes
3. With the Bois de Boulogne
4. Without the Bois de Boulogne
5. 2005 is the year of the most recent official estimate; population of these arrondissements may still be growing
Each arrondissement is subdivided administratively into four quartiers. Paris thus has 80 quartiers administratifs, each containing a police station. For a table giving the names of the 80 quartiers, see fr:Quartier de Paris#Quartiers administratifs aujourd'hui.
History
Before 1860
Map showing the 12 old arrondissements. The surrounding grey area shows the size of Paris after the expansion in 1860.
On October 11, 1795, Paris was divided into 12 arrondissements. They were numbered from west to east, with numbers 1-9 situated on the right bank of the Seine, and 10-12 on the left bank.
Each arrondissement was subdivided into 4 quartiers, which corresponded to the 48 original districts created in 1790.
After 1860
On January 1, 1860, new territory was defined to be within the city by Napoleon III. The previous 12 arrondissements were rearranged with this new territory to become the present 20.
In references to historical records (where it is important to distinguish between the old and new systems), the old arrondissements are indicated by following the number with the term ancienne (e.g. 2ème ancienne or 7ème anc.).