This is one of the few museums that I would recommend going to not so much for its content but for the building itself- it is massive! There are displays on building and designing, but the central court is 16 stories high and as big as a football field! No wonder that it has been the place chosen for several presidential inauguration balls in the last few years, including Obama's.
Few people get to this museum, located some blocks northwest of the Capitol, but it's one of my favorites. The museum building itself is an amazing piece of architecture from both outside and inside. Its huge interior space serves as the site for one of the inaugural balls that mark the beginning of each US presidency. As a museum, this institution covers the history and current trends of building and architecture in America. The exhibits change regularly, so I go there every so often for a new take on a favorite topic. There are also interactive presentations occasionally: one on iron-working was in progress the last time I visited.