Persepolis or Takht-e Jamshid is an ancient city which has been the capital of the Achaemenid Empire. In 518 A.D., this massive building was constructed as the new capital of the Achaemenid Empire to the order of the Great Darius, the Achaemenid king. Most knowledge on the Achaemenid Empire and the culture of that era is obtained from adobe engravings, petroglyphs and metal engravings discovered from Persepolis palaces. According to the adobe engravings discovered from Persepolis, numerous architects, artisans, artists, laborers, men and women participated its construction and they had been gathered from various nations and they were under insurance coverage in addition to their wages and salary. Major palaces and buildings in Persepolis include Apadana Palace, Tachar Palace, Hadish Palace, Malakeh Palace, H Palace, Se Dar Palace, Sad Sotoon Palace, and the Imperial Treasury Building. Persepolis has been registered in UNESCO World Heritage Center.