The 1st arrondissement of Paris is one of the 20 arrondissements (administrative districts) of the capital city of France. Situated principally on the right bank of the River Seine, it also includes the west end of the Île de la Cité. The arrondissement is one of the oldest in Paris, the Île de la Cité having been the heart of the city of Lutetia, conquered by the Romans in 52 BC, while some parts on the right bank (including Les Halles) date back to the early Middle Ages.
It is the least populated of the city's arrondissements and one of the smallest by area, a significant part of which is occupied by the Louvre Museum and the Tuileries Gardens. Much of the remainder of the arrondissement is dedicated to business and administration. The 1st arrondissement is very small, with a land area of only 1,83 km2 (0.705 sq. miles, or 451 acres).
The area now occupied by the first arrondissement attained its peak population in the period preceding the re-organization of Paris in 1860. In 1999, the population was 16,888, while the arrondissement hosted 63,056 jobs, making it one of the most active for business after the 2nd, 8th, and 9th.