Library of Congress

The Main Reading Room of the Jefferson Building has one of the best interiors in DC, and most visitors don't know there's a free public gallery overlooking it.

What you can actually see

The building is open to the public. The Main Reading Room itself is for registered researchers, but there's a visitor gallery above it where you can look down over the whole space: the dome, the arched windows, the reading tables below. It takes about 15 minutes and the sight is worth the detour.

The rest of the building has rotating exhibitions, a gift shop, and a café. Everything is free. The exhibitions vary in quality but the architecture alone justifies the stop.

Practical notes

Jefferson Building is on First Street SE, across from the Capitol. Open Monday through Saturday. You go through a security checkpoint; bags are allowed. Capitol South Metro is a 5-minute walk. Give yourself at least an hour if you want to see the reading room gallery and an exhibition.