A ziggurat is a temple of ancient Mesopotamia that has the shape of a pyramid. The design of a ziggurat goes from a simple base with a temple on top. The base could be rectangular, oval or square. The ziggurat's core - the part not exposed to the weather - was built of sun-dried bricks, while the outer part was covered with cooked bricks, which could also be vitrified in different colors; the access was made by stairs located on the sides of the ziggurat or spiraling up to the top. One of the best preserved is that of Choga Zanbil in present-day Iran, in the territory between Iraq and Iran. The oldest preserved ziggurat is that of Kashan dating back to the third millennium BC.
