We were a few miles from downtown DC, but we were lucky enough to be walking distance from the bus stop which took us straight to the Metro! If you every want to travel to DC stay on the outskirts and take advantage of the Metro.
At the Air and Space Museum we watch a 3D movie in the IMAX theater about the Hubble telescope. It was very cool! The Natural History Museum had a new exhibit on the origins of humans. We had lunch there as well. All the Museums have a cafe or cafeteria. The best thing was most of the food was local, sustainable and organic. Plus the majority of the paper and plastic ware was made of recycled material and was biodegradable. I wasn't able to take any pictures at the National Archives so I was only able to take one of the building.