Frank Lloyd Wright is one of America’s best-known architects. He designed private houses, religious buildings, museums and other public structures throughout America during the 1900s. His buildings were created to be a part of their natural surroundings, what he called organic architecture. Years later, his work still appears strikingly modern. Recently, “The 20th Century Architecture of Frank Lloyd Wright” was added to the list of UNESCO World Heritage Sites. UNESCO says the list contains places that are considered to have outstanding universal value to humanity. However, it is unusual for the work of a single architect to be placed on the list. “I think Wright's work was unique because he was unique,” said architectural historian William Richards.