Paris (UK: ; US: ; French: ) is the capital and most populous city of France. Situated on the Seine River, in the north of the country, it is in the centre of the Île-de-France region, also known as the région parisienne, “Paris region”. The City of Paris has an area of 105.4 km2, and as of January 2013, a population of 2,273,305 people. With an estimated 10,843,285 inhabitants as of 2015, Paris’s urban area is the most populous in the European Union, and third most populous in Europe, behind Moscow and Istanbul. Paris was founded in the 3rd century BC by a Celtic people called the Parisii, who gave the city its name. By the 12th century, Paris was the largest city in the western world, a prosperous trading centre, and the home of the University of Paris, one of the first in Europe. In the 18th century, it was the centre stage for the French Revolution, and became an important centre of finance, commerce, fashion, science, and the arts, a position it still retains today. The Paris Region has a GDP of €612 billion (US$760 billion) in 2012, ranking it as one of the wealthiest five regions in Europe; it is the banking and financial centre of France, and contains the headquarters of 30 companies in the Fortune Global 500. In 2013 the City of Paris received 29.3 million visitors, making it one of the world’s top tourist destinations. Paris is the home of the most-visited art museums in the world, the Louvre, as well as the Musée d’Orsay, noted for its collection of French Impressionist art, and the Musée National d’Art Moderne, a museum of modern and contemporary art. The notable architectural landmarks of Paris include the Notre Dame Cathedral (12th century); Sainte-Chapelle (13th century); the Eiffel Tower (1889); and the Basilica of Sacré-Cœur on Montmartre (1914). Paris is known for its fashion designers and the twice-yearly Paris Fashion Week, and for its haute cuisine, and three-star restaurants. Most of France’s major universities and Grandes écoles are located in Paris, as are France’s major newspapers, including Le Monde, Le Figaro, and Libération. Paris is home to the association football club Paris Saint-Germain F.C. and the rugby union club Stade Français. The 80,000-seat Stade de France, built for the 1998 FIFA World Cup, is located in Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros. Paris played host to the 1900 and 1924 Summer Olympics, the 1938 and 1998 FIFA World Cups, and the 2007 Rugby World Cup. The city is a major rail, highway, and air-transport hub, served by the two international airports Paris-Charles de Gaulle and Paris-Orly. Opened in 1900, the city’s subway system, the Paris Métro, serves 9 million passengers daily. Paris is the hub of the national road network, and is surrounded by three orbital roads: the Périphérique, the A86 motorway, and the Francilienne motorway in the outer suburbs.