 Graycliff is one of only five of Frank Lloyd Wright’s designs that were built between 1925 and 1935, and the only Wright designed structure built between Taliesin (1925) and Fallingwater (1936) using stone.Wright believed stone to be the only true building material and may be why he insisted the Martins incorporate it at Graycliff.Graycliff is considered to be one of Wright's most important mid-career works in his Organic Style.