If you wanted to study a skyscraper designed by famous architect Frank Lloyd Wright, this is where you would have to come. Finished in 1956, this is the only one he designed that was actually built. It was constructed in Bartlesville, Oklahoma as the world headquarters of the H.C. Price Co., an oil industry construction firm. Wright’s extensive use of copper gives the tree inspired building a lovely green patina. The tower now houses a museum on the lower floors and a boutique hotel and restaurant on the upper floors.