In the far southwest corner of Pennsylvania, Frank Lloyd Wright’s Fallingwater gets most of the architectural attention. And that is absolutely deserved, because it is a masterpiece. However, just down the road is a much more subdued example of his architecture, which is every bit as grand in its own way. It is a humble Usonian, with no waterfall, but nevertheless is a house which perfectly displays Wright’s architectural ideals. No pilgrimage to this area is complete without as stop at Kentuck Knob. Completed in 1956 by a then 86 year old Frank Lloyd Wright, it was one of his last projects. The house was built for Bernadine and Issac…