Built in 1765, the capital’s oldest surviving building has been a tavern, brothel and boardinghouse (sometimes all at once). Today it's a small museum offering a peek into Revolutionary War–era life. The evocative little garden in back is worth a mosey.
It was almost demolished in the 1950s, but a persistent (albeit false) rumor that Pierre L’Enfant used it as a workshop while designing DC saved it for posterity.