Final answer:
A ziggurat is a temple tower of the ancient Mesopotamian valley, having the form of a terraced pyramid of successively receding stories. They were significant architectural structures in Mesopotamia.
Step-by-step explanation:
A ziggurat is a temple tower of the ancient Mesopotamian valley, having the form of a terraced pyramid of successively receding stories. Ziggurats were built using earthen materials, such as mud-brick, and often supported a temple or shrine. They were a significant architectural form in Mesopotamia and served as monumental ceremonial centers in cities.