Paris for 31 percent of the GDP of France. According to the Economist Intelligence Unit Worldwide Cost of Living Survey in 2018, Paris was the second-most expensive city in the world, behind Singapore and ahead of Zurich, Hong Kong, Oslo and Geneva. 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 69.5 million passengers in 2017) 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
Paris–Le Bourget Airport commercial brand Paris Aéroport was applied to all Parisian airports, including Le Bourget airport. The Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile (BEA) is headquartered in Building 153 on the grounds of Le Bourget Airport and in Le Bourget. Le Bourget Airport hosts the Musée de l'Air et de l'Espace, which is also located in the commune of Le Bourget. Paris–Le Bourget Airport Paris–Le Bourget Airport () is an airport located within portions of the communes of Le Bourget, Bonneuil-en-France, Dugny and Gonesse, north-northeast (NNE) of Paris, France. Once Paris's principal airport, it is now used only