Persian domes or Iranian domes have an ancient origin and a history extending to the modern era. The use of domes in ancient Mesopotamia was carried forward through a succession of empires in the Greater Iran region. An ancient tradition of royal audience tents representing the heavens was translated into monumental stone and brick domes due to the invention of the squinch, a reliable method of supporting the circular base of a heavy dome upon the walls of a square chamber. Domes were built as part of royal palaces, castles, caravansaries, and temples, among other structures.