One of the most underestimated museums in town, the Marmottan is Paris's "other" Impressionist museum (after the Musée d'Orsay). A few years ago this elegant 19th-century mansion tacked claude monet onto its official name -- and justly so, as this may be the best collection of the artist's works anywhere. Monet occupies a specially built basement gallery, where you'll find such captivating works as the Cathédrale de Rouen series (1892-96) and Impression: Soleil Levant (Impression-Sunrise, 1872), the work that helped give the Impressionist movement its name. Other exhibits include letters exchanged by Impressionist painters Berthe Morisot and Mary Cassatt. There's a roomful of priceless illuminated medieval manuscripts on the ground floor. Empire furniture makes you feel as if you're at an actual Napoleonic salon, with comfortable couches and windows overlooking the Jardin de Ranelagh on one side and the hotel's private yard on the other. For complete information in English, buy a catalog in the museum shop on your way in. COST: EUR6.50. Métro: La Muette.