We spent 3 days exploring the Smithsonian museum complex in Washington DC. All 12 museums are free to enter which is great for educating the public about a variety of subjects.
We spent a lot of time in the Natural History Museum and here at the Smithsonian National Air and Space Museum. Over 2 days we watched d6 IMAX movies, the best was Hubble 3D.
We really enjoyed our time here in this great city.