Paris 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, music and painting. The Paris Region had a GDP of €681 billion (US$850 billion) in 2016, accounting for 31 per cent of the GDP of France. In 2013–2014, the Paris Region had the third-highest GDP in the world and the largest regional GDP in the EU. The city is a major rail, highway, and air-transport hub served by two international airports: Paris-Charles de Gaulle 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 2017, with 8.1 million visitors. The Musée d’Orsay and Musée de l’Orangerie are noted for their collections of French Impressionist art, and the Pompidou Centre Musée National d’Art Moderne has the largest collection of modern and contemporary art in Europe. The historical district along the Seine in the city cen tre is classified as a UNESCO Heritage Site. Popular landmarks in the centre of the city include the Cathedral of Notre Dame de Paris and the Gothic royal chapel of Sainte-Chapelle, both on the Île de la Cité, the Eiffel Tower, constructed for the Paris Universal Exposition of 1889; the Grand Palais and Petit Palais, built for the Paris Universal Exposition of 1900; the Arc de Triomphe on the Champs-Élysées, and the Basilica of Sacré-Coeur on the hill of Montmartre. Paris received 23 million visitors in 2017, measured by hotel stays, with the largest numbers of foreign visitors coming from the United States, the UK, Germany and China. It was ranked as the third most visited travel destination in the world in 2017, after Bangkok and London. The football club Paris Saint-Germain and the rugby union club Stade Français are based in Paris. The 80,000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the neighbouring commune of Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros. Paris hosted the Olympic Games in 1900, 1924 and will host the 2024 Summer Olympics. The 1938 and 1998 FIFA World Cups, the 2007 Rugby World Cup, and the 1960, 1984, and 2016 UEFA European Championships were also held in the city and, every July, the Tour de France bicycle race finishes there.