Frank Lloyd Wright's Fallingwater in Pennsylvania.

Visit to Mill Run, Pennsylvania, Frank Lloyd Wright's famous house designed for the Kaufman family. A beautiful, if long November drive from Alexandria led us to a tour of the most famous house in the United States, not because of who lived there, but who designed it, and its unique setting. It really is a beautiful house, in a nice canyon. The scale was bigger than I thought, 4 bedrooms, but huge terraces and an guest house with a pool up the hill. Everything is built-in and "human scale" inside, low ceilings, cleaver windows, everything attached horizontally to the walls. Not 100% practical, but very cool looking. The family rejected his rigid chairs for 3-legged antiques, which are much more practical for the uneven flagstone floors. Great tour worth the time, but wish we stayed a weekend as he designed another house down the road and there are outdoor activities like horseback-ridding and rafting very near by.