We went to Mill Run, Pennsylvania to see Frank Lloyd Wright's masterpiece, Fallingwater. The house lived up to its reputation and was well worth the 3 hour drive (each way) to get there. The approach to the site is an incredibly peaceful, long, forested drive. From the visitors center, you walk further into the wooded area, still without seeing the house.
In the first view of the house, it's unclear where to enter. The house is stacked up the hillside, with the river and waterfall below.