In 2000, Fallingwater was named "The Building of the 20th century" in "Top-Ten" poll taken by members attending the AIA annual convention in Philadelphia, Pennsylvania. On that list, Wright was listed along with many of the USA's other greatest architects including Eero Saarinen, I. M. Pei, Louis Kahn, Philip Johnson and Ludwig Mies van der Rohe. He was the only architect who had more than one building on the list. The other three buildings were the Guggenheim Museum, the Frederick C. Robie House and the Johnson Wax Headquarters.