The Western Pennsylvania Conservancy (WPC) is a private nonprofit conservation organization founded in 1932 and headquartered in Pittsburgh. WPC has contributed land to 12 state parks, conserved more than of rivers and streams. In 1963, Edgar Kaufmann jr. entrusted Frank Lloyd Wright's masterwork Fallingwater to WPC. The house was called the most important building of the 20th century by the American Institute of Architects and recently voted the most important building of the 20th century. - Source: Wikipedia