One of the premier art museums in the U.S., the National Gallery of Art is almost as famous for its glorious neoclassical marble building as it is for its collection of art. It features a huge domed rotunda, a colonnaded fountain, vaulted corridors, and elegant interior gardens. The art collection is impressive too, with paintings, decorative arts, and sculpture dating from the middle ages to current times. Vermeer, Michelangelo, El Greco, Homer, and Cassatt are all featured in the West Building. The East Building is home to art from the 20th Century, with Picasso, Matisse, Van Gogh, and Pollack among the permanent collection. Be sure to visit the sculpture garden across the street, with a relaxing fountain, reflecting pool, and cafe. Admission is free.