North side of the Mall, Constitution Ave between Third and Seventh streets NW; closest Metro Archives-Navy Memorial. Mon-Sat 10am-5pm, Sun 11am-6pm. 202/737-4215. Admission free.

Though the visually stunning National Gallery of Art, the nearest of the Mall museums to the Capitol, is not in fact a government institution, it fully deserves its name. It owes its prominence to the efforts of industrialist Andrew Mellon, who bought the building and donated most of the paintings (many were purchased from the cash-poor post-revolutionary government of the USSR, where they had previously hung in the Hermitage). His family have continued as benefactors, raising countless millions to build I M Pei's modernistic East Building in 1978.

The original Neoclassical gallery, designed by John Russell Pope in 1941, is now called the West Building and holds the bulk of the permanent collection. It's currently undergoing a major restoration program, in which rooms on the main floor will be closed in rotation, and the relevant works relocated to the ground floor - this process will last until at least 1999, so whenever you visit, some major part of the collection will not be on show in its assigned place.

From the domed central rotunda, where you can pick up a floor plan and gallery guide, a vaulted corridor runs the length of the building. If you only have limited time, latch onto one of the informative daily free tours - ask for a schedule at the information desk. Galleries to the west on the main floor display major works by Renaissance masters, arranged by nationality: half a dozen Rembrandts fill the Dutch gallery, Van Eyck and Rubens dominate the Flemish, and El Greco and Velázquez face off in the Spanish, near eight progressively darker Goyas. There's also the only Leonardo in the US, the 1474 Ginevra de' Benci, painted in oil on wood, plus works by Botticelli, Crivelli and Raphael - including the latter's celebrated Alba Madonna (1520), one of Mellon's purchases from the Hermitage. The other half of the West Building holds an exceptional collection of nineteenth-century French paintings - Gauguin from Pont-Aven to Tahiti, a couple of Van Goghs, some Monet studies of Rouen Cathedral and water lilies, Cézanne still-lifes et al. At either end of the building, the skylit, fountain-filled Garden Courts make an ideal place to rest weary feet, while Salvador Dalí's Last Supper guards the escalators down to the cafe.

The triangular East Building houses twentieth-century paintings and sculpture. As in the Guggenheim in New York, the attention-grabbing spatial choreography of the architecture all but overpowers the works of art. You emerge from under the oppressively low entrance into a central atrium, from where an escalator, literally carved out of a 40ft granite wall, climbs to the main galleries - which, squeezed into the corners, can seem like an afterthought. Changing and touring exhibitions throughout the year mean that the bulk of the permanant collection is rarely on display, though you may catch Picasso's haunting Family of Saltimbanques and the very blue The Tragedy, as well as Giacometti bronzes and paintings, plenty of Alexander Calder (whose huge red-and-black mobile is usually in place), early Mirós, some Warhol soup cans and Chuck Close's finger painting par excellence, Fanny. The underground concourse that links the two buildings contains a good bookstore, an espresso bar and a large cafeteria - topped by pyramidal skylights and bordered by a glassed-in waterfall.