What better setting for a world-class museum of 19th-century art than a beautiful example of Belle Epoque architecture? In 1986, the magnificent Gare d’Orsay train station, built to coincide with the 1900 World’s Fair, was brilliantly transformed into an exposition space. The huge, airy central hall lets in lots of natural light, which is artfully combined with artificial lighting to illuminate a collection of treasures.

The collection spans the years 1848 to 1914, a period that saw the birth of many artistic movements, but today it is best known for the emergence of Impressionism. All the superstars of the epoch are here, including Monet, Manet, Degas, and Renoir, not to mention Cézanne, and Van Gogh.

The top floor is now the home of the most famous Impressionist paintings, like Edouard Manet’s masterpiece, “Le Déjeuner sur l’Herbe.” Though Manet’s composition of bathers and friends picnicking on the grass draws freely from those of Italian Renaissance masters, the painting shocked its 19th-century audience, which was horrified to see a naked lady lunching with two fully clothed men. Manet got into trouble again with his magnificent “Olympia,” a seductive odalisque stretched out on a divan. There was nothing new about the subject; viewers were rattled by the unapologetic look in her eye—this is not an idealized nude, but a real woman, and a tough cookie to boot.

The middle level is devoted to the post-Impressionists, with works by artists like Gauguin, Seurat, Rousseau, and Van Gogh, like the latter’s “Church at Auvers-sur-Oise,” an ominous version of the church in a small town north of Paris where he moved after spending time in an asylum in Provence. This was 1 of some 70 paintings he produced in the 2 months leading up to his suicide.