If you only visit one art museum in DC, make it the Reynolds Center, which combines the National Portrait Gallery and the American Art Museum. There is, simply put, no better collection of American art in the world than at these two Smithsonian museums. Famed works by Edward Hopper, Georgia O’Keeffe, Andy Warhol, Winslow Homer and loads more celebrated artists fill the galleries.
Be sure to hit the Luce Center on the 3rd and 4th floors: the open storage area stuffed with more than 3000 paintings, sculptures, miniatures and folk-art pieces makes for glorious browsing. The museum's 1st-floor inner courtyard, roofed with slanting glass and dotted with trees and peaceful fountains, is another lovely spot. Bring your own picnic or order sandwiches at the cafe.