Fallingwater: Mill Run, PA, USA
Frank Lloyd Wright's Fallingwater home design

Frank Lloyd Wright designed Fallingwater, which was completed in 1939 and sits over a waterfall in Pennsylvania.

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In the late 1930s, Pittsburgh department-store owner Edgar Kaufmann, Sr., commissioned noted architect Frank Lloyd Wright to build a weekend retreat on the family's property, located along Bear Run in Pennsylvania's Laurel Highlands. The result was Fallingwater, a home that many consider a foundational example of marrying a home with its natural surroundings.

One of Fallingwater's most prominent features is its placement: The house is cantilevered over a cascade of waterfalls. In his notes, Wright states that he wished the family to "live with the falls," rather than simply seeing them from a distant window [source: Western Pennsylvania Conservancy]. From some angles, the house appears to be a natural outgrowth of the rock formations along Bear Run. It juts slightly above the surrounding trees like a rock promontory and spreads naturally along the path carved over eons by the waterfall.

Fallingwater was a luxurious custom vacation home designed for a powerful, wealthy family. But its design influenced a generation of architects and homebuilders. The Case Study Houses of the post-World War II era incorporated the open structure and spacious windows that architects like Wright and Johnson pioneered. While primarily a design concern, these features were forerunners of the passive solar design found in Earthships and other modern green homes. The architectural art that's made Fallingwater a landmark building carries on, as much for its energy-conscious potential as for its sheer beauty [source: Western Pennsylvania Conservancy].