George Washington's Mount Vernon Estate and Gardens is a must see. Tour the mansion that Washington designed and built on the banks of the Potomac River. The estate also houses Washington's tomb and a winery that was operational when Washington lived here. Not far away to the north lies Arlington National Cemetery, the resting place for many of the country's soldiers. Visit the grave of John F. Kennedy and his family, along with the tomb of the unknown soldier.
Another must-do is cruising on the Potomac. Cruises, which take 45 minutes to an hour, take you past famous Washington monuments including the National Harbour, buildings from the 1700s and 1800s in historic Alexandria, the Jefferson Memorial, parts of the Pentagon, the Washington Monument, and Arlington Memorial Bridge.
The National Air and Space Museum, America's most visited, contains rare artifacts from aviation history that will engage you for hours. See the Apollo 11 command module, Charles Lindberg's iconic Spirit of St. Louis, Soyuz test modules, and other displays. Other must-sees include the Smithsonian National Museum of Natural History and the National Museum of African American History and Culture.