Paris (French pronunciation: [paʁi] (listen)) is the capital and most populous city of France, with an area of 105 square kilometres (41 square miles) and a population of 2,206,488. Since the 17th century, Paris has been one of Europe's major centres of finance, commerce, fashion, science, and the arts.
The City of Paris is the centre and seat of government of the Île-de-France, or Paris Region, which has an estimated official 2018 population of 12,246,234, or 18.2 percent of the population of France. Besides this, the Paris metropolitan area had a population of 12,532,901 in 2015. The Paris Region had a GDP of €681 billion (US$850 billion) in 2016, accounting for 31 percent of the GDP of France, and is the 5th largest city by GDP in the world. 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 Europe after Moscow Metro. Gare du Nord is the 24th busiest railway station in the world, with 262 million passengers in 2015.
Paris is often referred to as The City of Light (La Ville Lumière), both because of its leading role during the Age of Enlightenment, and more literally because Paris was one of the first large European cities to use gas street lighting on a grand scale on its boulevards and monuments. Gas lights were installed on the Place du Carousel, Rue de Rivoli and Place Vendome in 1829. By 1857, the Grand boulevards were lit.  By the 1860s, the boulevards and streets of Paris were illuminated by 56,000 gas lamps. Since the late 19th century, Paris has also been known as Panam(e) (pronounced [panam]) in French slang.