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 centre 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.