Neoclassical (1816) Georgetown mansion, home of Martha Washington’s granddaughter, and 5.5-acre gardens. National Historic Landmark with largest collection of George Washington’s personal items outside Mount Vernon. Garden tours ($3), teas, talks, events; see website for calendar. Guided tours on the hour. Tu-Sa 10 am-4 pm, Su noon-4 pm (last tour 3 pm). $3-$10, children under 5 free. Self-guided garden-only tour $3.