Fodor's Expert Review Dumbarton House

Not to be confused with the Dumbarton Oaks museum, a beautiful garden and research center a few blocks away, this circa-1799 brick mansion was once the home of the first U.S. Register of the Treasury, Joseph Nourse. Today it's the headquarters for The Colonial Dames of America. Visitors can tour the antiques-filled Federalist home, which often hosts concerts, theatrical performances, and other community events. Docent-led tours are available on the weekend, and the house is open for self-guided tours from Friday to Sunday. Timed tickets are required.