Fallingwater, also known as the Edgar J. Kaufmann Sr. Residence, is a house designed by American architect Frank Lloyd Wright in 1934 in rural southwestern Pennsylvania, 50 miles southeast of Pittsburgh, and is part of the Pittsburgh Metro Area.
The house was built partly over a waterfall in Bear Run at Rural Route 1 in the Mill Run section of Stewart Township, Fayette County, Pennsylvania, in the Laurel Highlands of the Allegheny Mountains. The Kaufmanns owned some property outside Pittsburgh with a waterfall and some cabins. When the cabins at their camp had deteriorated to the point that something had to be rebuilt, Mr. Kaufmann contacted Wright.
The structural design for Fallingwater was undertaken by Wright in association with Mendel Glickman and William Wesley Peters who had been responsible for the design of the revolutionary columns which were a feature of Wright's design for the Johnson Wax Headquarters. For the cantilevered floors Wright and his team used integral upside-down beams with the flat slab on the bottom forming the ceiling of the space below. In October 1937 the main house was completed. Fallingwater was the family's weekend home from 1937 to 1963.
In 1963, Kaufmann, Jr. donated the property to the Western Pennsylvania Conservancy. In 1964 it was opened to the public as a museum and nearly five million people have visited the house since (as of January 2008). It currently hosts more than 120,000 visitors each year.