Paris (French pronunciation: [paʁi](listen)) is the capital and most populous city of France, with a population of 2,140,526 residents (official estimate, 1 January 2019) in an area of 105 square kilometres (41 square miles). Since the 17th century, Paris has been one of Europe's major centres of finance, diplomacy, 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 2019 population of 12,213,364, or about 18 percent of the population of France. The Paris Region had a GDP of €709 billion ($808 billion) in 2017. According to the Economist Intelligence Unit Worldwide Cost of Living Survey in 2018, Paris was the second most expensive city in the world, after Singapore, and ahead of Zürich, Hong Kong, Oslo and Geneva. Another source ranked Paris as most expensive, on a par with Singapore and Hong Kong, in 2018.
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.