Often confused with Dumbarton Oaks (the mansion and gardens), Dumbarton House is a modest Federal-style historic home, constructed by a wealthy family in 1799. Now it’s run by the National Society of the Colonial Dames of America, who have their headquarters here. The focus isn’t just the house – chockablock with antique china, silver, furnishings, gowns and books – but also quaint customs of the era, like passing round the chamber pot after formal dinners so gentlemen could have a group pee.
Visiting on the weekend for a 45-minute guided tour (held at 10:30am and 1:30pm Saturday and Sunday) provides the biggest bang for the buck; it’s best to reserve online in advance (there’s no fee). The landscaped grounds offer a pleasant browse. They’re open from sunrise to sunset and are free to walk through.