Fallingwater is considered the most important American house since Monticello and one of the most important buildings of the twentieth century. It is the dramatic synthesis of a remote natural site, innovative design, and dynamic relationship between architect and patron. The house was built between 1934 and 1937 as a weekend retreat for department store owner Edgar J. Kaufmann, his wife, Liliane, and son, Edgar. Frank Lloyd Wright cantilevered the house over Bear Run's waterfall on a tract of wooded mountain land formerly used as the Kaufmann Department Store's employee summer camp. He mimicked the local layered rock strata with quarried sandstone defined by smooth concrete cantilevers separated by plate glass and steel. A boulder near the waterfall was incorporated into the basement walls of the house to make a rugged hearth for the living room fireplace. A canopy, guest house, and servant's quarters extend like an outstretched arm up the hillside behind the main portion of the house. Wright's internationally renowned design gave the Kaufmanns an intimate union with nature and the waterfall they loved. Forty years after Fallingwater's completion, the Western Pennsylvania Conservancy, given the house by Edgar Kaufmann Jr., commissioned furniture designer Paul Mayen to design a visitors' center relating to the house, but not conflicting with it. Mayen worked with architects Curry, Martin and Highberger to build a concrete, cedar, and glass design raised above the ground and ecologically mindful. Its trio of pavilions houses a restaurant, museum shop, and permanent exhibition space.
Near the entrance to Fallingwater, on the east side of PA 381, two older Kaufmann barns were adapted as sustainable offices and a community center by Bohlin Cywinski Jackson for the Conservancy. The reuse was given a Green Design Citation and awarded the Pittsburgh Chapter of the American Institute of Architects 2005 Silver Medal as an extraordinary work of architecture. Further information on Fallingwater can be found in the numerous publications on this house.