Ziggurats were a type of ancient temple built by the ancient Babylonians and Assyrians in the Mesopotamia region. According to Livius, these structures are essentially "temple towers," and many rose incredibly high into the sky. Built by kings as late as 1640 B.C., ziggurats were thought to provide a connection between Earth and the heavens. They were also a way for kings to demonstrate their power to their people.
The basic structure of a ziggurat, according to Reference.com, is a pyramid-like tower that has a number of stories which can be ascended via a structure that winds around the outside of the tower. This winding staircase around the outside of the tower makes the ziggurat appear as though it is a series of terraces. These structures were built from stone that was quarried from the surrounding areas.
Livius describes several ziggurats that are still standing today. The best preserved of these is located in what is now Khuzestan in Iran. Another is Etemenanki, found in Babylon. The name "Etemenanki" means "House of the foundation of heaven on Earth." Ziggurats were important in the culture and religion of Mesopotamian cities. Nineteen of the temples were found in just 16 different cities, and the existence of 10 more is documented in various historic texts.