"Silver Hill: This is outside town, but it's where the Smithsonian Air & Space Museum stores and restores aircraft. I saw the Enola Gay, as well as other aircraft here. Tours are by reservation, but aircraft nuts guide you."

New annex out by Dulles, in VA. No reservation, but $12 to park ( per vehicle). They moved most of the contents of Silver Hill, and got the Shuttle Enterprise and a Pegasus.

College Park Airport has a nice little museum ( 1902 Wright glider, 1908 Wright Flyer, Jenny, 1 1/2 Ercoupes, and a few others. Oldest "active" comercial airport.