This is the annex of the Air and Space Museum that's in DC. The aircraft/Spacecraft are some of the collection that were too big for display in WDC. One of the space shuttels that flew in space was just moved in. One of the Concorde SSTs is here along with an SR-71 that set speed records. Since the museum is located between two of the runways at Washington Dulles there are opportunities to view the aircraft on final approach. ( 1 p.m. to 3 p.m. is a good time to watch for transatlantic arrivals.) There is also a "control tower" where you can watch the flights arriving and taking off and hear an audio feed from the Dulles tower.