The date of the earliest ziggurats is likely in the late Early Dynastic era, particularly Early Dynastic III. Early Dynastic III seals sometimes depict ziggurats, or altars shaped as miniature ziggurats, topped by some sort of miniature shrine. At Nippur and Kish there is meager evidence of late Early Dynastic ziggurats. The presence of Early Dynastic shrines around the Ur ziggurat strongly suggests that it is piously built over an ED ziggurat, much like temple platforms which were built one above the other. There may be unexcavated ziggurats elsewhere in Sumer, but at Uruk is has been proven that no ziggurat existed before Ur-Nammu's construction of one. Regardless, it was under the reign of Ur-Nammu that ziggurat construction began on a massive scale, with ziggurats being erected at Nippur, Ur, Uruk, Larsa and Eridu. Construction was part of Ur-Nammu's public policy of providing jobs, and ziggurat construction in particular reinforced his role as a liaison to the divine. Their monumental nature both is a reflection and a manifestation of Ur-Nammu's consolidation of power. As the first Ur III king, the surviving ziggurats at Nippur, Ur, Uruk, Larsa and Eridu were thus begun at the very end of the 3rd millennium BC and completed under his son Shulgi; this is revealed by mudbricks and clay nails stamped with his name.
Sumerian ziggurats are typified by the ziggurat at Ur, which is their best-preserved example. The ziggurat was of unbaked mud-brick (likely enclosing an earlier ziggurat) with a 2.4 m skin of baked brick set in bitumen, with a niched and buttressed façade that was originally plastered. There are so-called weeper holes puncturing the ziggurat to its core, but their exact function is debated. The first stage measured 61 x 45.7 m at ground level and rose 11 m above ground level. Two stairways rose from the front corners, while another ran perpendicular to these in the middle; the three stairways met at a covered area a few meters below the first terrace, from where a single stairway proceeded all the way up past the second terrace 5 m above the first and the third 2.9 m above that one. Circumstantial evidence indicates that atop the ziggurat was a shrine to Nanna, but no physical evidence has been discovered. Prior monumental platforms invariably supported a shrine, and cylinder seals depict ziggurats which appear to have a shrine atop them. Also, Herodotus described that atop the Babylon ziggurat was a shrine to Marduk with a golden couch, on which a woman spent the night and Marduk would come sleep in his shrine with her. Next to the Ur ziggurat was the giparu, home of Nanna's earthly wife the entu, so the entu could live next to her divine husband.
Ziggurats were within a walled temenos, and often accompanied by other structures. Within the Ur temenos there was the giparu, and immediately outside the temenos wall was a trash heap which became an ideal spot for burials (including the Royal Cemetery itself) due to its proximity to the holy site and lack of buildings. Within the Nippur religious quarter there was the North Temple.
Dedicated to Enlil and Ninlil, built by Ur-Nammu.
Dedicated perhaps to Shara.
Dedicated to Inanna, built by Ur-Nammu.
Dedicated to Utu, built by Ur-Nammu.
Dedicated to Nanna and Ningal, built by Ur-Nammu.
Dedicated to Enki, built by Ur-Nammu.
Early Bronze Age
Old Babylonian period heralds examples from the north, such as Tell Rimah near Sinjar.
Late Bronze Age
Southwest Iran near Susa, there ziggurat style building dating to the second half of the second millennium at Chogha Zanbil.
The ziggurat of Assyrian cities was less prominent than ziggurats in Babylonian cities.
Similar ziggurat style structures at Altyn Tepe in Turkmenia and Mundigak in Afghanistan.