The cantilever architecture of Frank Lloyd Wright's Fallingwater makes it appear like the home is floating over the falls of Bear Run in western Pennsylvania. The home was designed for the Kauffmans - owners of a famous Pittsburgh department store - as their summer camp. The Kaufmann's wanted the home to have a view of the falls, but Wright incorporated the falls in to the house so the owners could live with them every day, not view them every now and again.
The home is a 90 minute drive from Pittsburgh (2 hours if you take scenic state roads instead of the freeway) and a perfect day trip from Steel City. Purchasing tickets online is highly recommended as tours can sell out.