This is the world's greatest art museum, and certainly one of the largest. The extraordinary collections are divided into Asian antiquities, Egyptian antiquities, Greek and Roman antiquities, sculpture, objets d'art, paintings, and prints and drawings. The quality and the sheer variety are overwhelming. The number one attraction is Leonardo's enigmatic Mona Lisa (La Joconde to the French). A highlight of the ancient Greek collection is the legendary Venus de Milo, from the 2nd century BC. Try to make repeat visits -- the Louvre is about one-third cheaper on Sunday (free the first Sunday of each month) and after 3 PM on other days. Study the plans at the entrance to get your bearings and pick up a map to take with you. It's faster to enter through the Carrousel du Louvre mall on rue de Rivoli than through the pyramid. Hours of operation change frequently, so make sure to call ahead or check the web site before visiting. COST: EUR10, EUR8 after 3 PM and all day Sun., free 1st Sun. of month, EUR5 for Napoléon Hall exhibitions. Thurs.-Sun. 9-6, Mon. and Wed. 9 AM-6 PM. Closed Tuesday. Hours change frequently -- check in advance. Métro: Palais-Royal.