This ziggurat was erected to the moon god Nanna. It was built by Ur-Nammu at Ur around 2113-2096 B.C. It was composed of three stages. It is not clear whether there was a temple at the top. The remains of the ziggurat probably stood over an existing structure going back to the early dynastic period, and restored by the Neo-Babylonian king Nabonidus (556-539 B.C.). It is the most preserved of all ziggurats in Mesopotamia and has been partially reconstructed reaching a hight of 11 m. It stood within a rectangular court 62.5 m x 43 m. at the base. Its outer faces are of baked brick, are inclined to a pronounced batter and have regularly spaced, flat buttresses. These outer faces encase the solid core of mudbricks. Access to the ziggurat was through three converging ramps from where a central stairway continued to the second stage. The shape of the staircase leading to the third stage is unclear.