The Musee d'Orsay in Paris is the greatest collection of Impressionist and Post-Impressionist art in the world — a magnificent museum housed in a converted Beaux-Arts railway station on the banks of the Seine whose soaring glass roof, ornate ironwork, and monumental spaces provide a spectacular setting for the greatest concentration of works by Monet, Renoir, Degas, Pissarro, Sisley, Manet, Van Gogh, Gauguin, Cezanne, Seurat, and their contemporaries that can be found anywhere on earth. The museum occupies the former Gare d'Orsay, built for the 1900 Paris Universal Exhibition, whose operational life as a railway station ended in 1939 and which fell into disrepair until its conversion into a museum in 1986 — the transformation is one of the most successful museum conversions in history, with the station's original architecture preserved and celebrated while the spaces have been reorganized to create a series of galleries that move visitors through the development of Western art from 1848 to 1914. The Impressionist collection on the top floor — natural light flooding through the glass roof, the works arranged to show the development of the movement from its origins in Barbizon painting through its flowering in the canvases of the 1870s and 1880s to the Post-Impressionist explorations of Cezanne and Van Gogh — is one of the most extraordinary sequences of gallery rooms in any museum in the world, a sustained encounter with the greatest period of innovation in the history of Western painting. Among its greatest individual works are Manet's Olympia and Dejeuner sur l'herbe, Van Gogh's Self-Portrait, Whistler's Arrangement in Grey and Black No. 1 (Whistler's Mother), and Renoir's Dance at Le Moulin de la Galette.