Tchogha Zanbil (the City of Untash, in Elamite) is the largest ziggurat outside of Mesopotamia and one of the best types of stepped pyramidal monuments. It is located near the ancient city of Susa in Khuzestan province of Iran. The ruins of Tchogha Zanbil is the sole testimony to the architectural development of middle Elamite period. Image by Richard Weil by C.C