Visit the Smithsonian museums. Two of the best are unquestionably the magnificent "Castle," home base of the superb institution, and the National Air and Space Museum. The National Museum of Natural History is another wonder, with the Hope Diamond and a Hall of Dinosaurs just part of the fun.
Set aside a few hours for the National Mall, where you can see a number of famous icons, including the Lincoln Memorial, Vietnam Memorial and the Washington Monument.
Drop by the National Archives, where you'll have the opportunity to view three of the most important documents in U.S. history: the Declaration of Independence, the U.S. Constitution and the Bill of Rights.
Spend an afternoon in the Dupont Circle neighborhood, a sophisticated sector with top-notch restaurants, fine museums and eye-catching embassies. Popular with the gay-and-lesbian community, the area is centered around a wonderful white-marble fountain a bit north of downtown.
Visit the National Zoo, another part of the Smithsonian and one of the city's most popular attractions. The sprawling complex is home to hundreds of species, including its famed giant pandas, Asian elephants, great cats and all manner of exotic birds - and admission is free!
Enjoy a night out in Georgetown, a historic old neighborhood with hip taverns and restaurants at every turn. Mr. Smith's and Nathan's are two popular hangouts with both locals and visitors.
See a show at the historic Ford's Theater, the site of Abraham Lincoln's assassination. Located on 10th Street NW, Ford's is a working theatre and a national historic site, showing new and classical musicals, dramas and comedies. Daily tours of the austere old theater-which re-opened in 1968 after sitting dormant for 103 years-are also available.
