Q: Which Smithsonian Air and Space? The one on the Mall or the Udvar Hazy? Assuming Mall any hotel between 15th Street and 7th St, G street and Constitution will work. Those are expensive addresses but also consider that the metro has a stop on the Mall so that will put you there as well. Georgetown has no metro access. If you want to save money look at metro stops around the Mall and go 3 or 5 stops out.