The City of Paris's administrative limits form an East- West oval centred on the island at its historical heart, the Île de la Cité; this island is near the top of an arc of the river Seine that divides the city into southern Rive Gauche (Left Bank ) and northern Rive Droite regions. Paris is the core of a built-up area that extends well beyond its limits: commonly referred to as the agglomération Parisienne, and statistically as a unité urbaine (a measure of urban area ), the Paris agglomeration's 2013 population of 10,601,122 made it the largest urban area in the European Union. City -influenced commuter activity reaches well beyond even this in a statistical aire urbaine de Paris (a measure of metropolitan area ), that had a 2013 population of 12,405,426, a number one-fifth the population of France, the largest metropolitan area in the Eurozone.
The city is a major rail, highway, and air - transport hub served by two international airports: Paris- Charles de Gaulle (the second busiest airport in Europe after London Heathrow Airport with 63.8 million passengers in 2014 ) and Paris-Orly. Opened in 1900, the city 's subway system, the Paris Métro, serves 5.23 million passengers daily, and is the second busiest metro system in Europe after Moscow Metro. Paris's Gare du Nord is one of the ten busiest railway stations in the world, with 262 million passengers in 2015.
Paris is especially known for its museums and architectural landmarks: the Louvre was the most visited art museum in the world in 2016, with 7.4 million visitors.
