The palace of Persepolis was planned and begun by the Persian emperor Darius I in the early fifth century BC, although it was not until the reign of his grandson, Artaxerxes, that it was finally finished around the year 425 BC. Conceived to be the seat of government for the Achaemenian kings and a center for receptions and ceremonial festivities. It was one of the great Persian temple complexes until it was destroyed by Alexander the Great in 331 BC. The ruins were not excavated until the Oriental Institute of the University of Chicago sponsored an archaeological expedition to Persepolis and its environs under the supervision of Professor Ernst Herzfeld from 1931 to 1934, and Erich F. Schmidt from 1934 to 1939. Persepolis was registered as a UNESCO World Heritage Site in 1979.
credit: Sajjadi Livejournal