[xsrdx]

My DC Area must sees:

American History Museum

Museum of Natural History

National Air & Space Museum (& Dulles Annex!)

NRA National Firearms Museum (Fairfax)

Arlington National Cemetary

Lincoln, Jefferson, Washington Monuments

Vietnam, Korean War, Iwo Jima (USMC) Memorials

Mount Vernon

International Spy Museum

Holocaust Museum

Take the Metro and TourMobile for downtown DC - way easier than walking and parking. Keep in mind all the downtown museums have metal detectors and security inspections.

[xsrdx]

As noted, Manassas National Battlefield park is a short drive, and a good combo day trip with the National Firearms Museum.

The Manassas Battlefield is usually very quiet, and has a first class Visitors Center.