After our trip to the National Air and Space Museum, we called it quits on our DC tourism. Our feet were starting to give out on us and it was about five-ish in the afternoon. I did spot the Smithsonian Castle which I think was the original museum before everything expanded while trying to find a good spot for the Lyft driver to pick us up. I kind of regret not really being able to see the place in detail though. My mind wanted to, but my feet had a different opinion.