Eridu was perhaps a thriving society during the Ubaid Period. The Ubaid Period lasted from around 5000 BC to 3900 BC. After that, it became primarily a religious site, constantly being abandoned, repaired, and abandoned again. It was finally completely abadoned after around 600 BC.

The Ziggurat at Eridu was built by king Amar-Sin, whose father famously built the Ziggurat at Ur. Eridu was the holy site for the god Enki. After Eridu was abandoned, the cult of Enki survived by moving to Ur during the time of the famous law giver Hammurabi.

The Sumerians, the worlds oldest known civilization, invented the first system of writing called Cuneiform. Cuneiform tablets, like the one pictured above, give archaeologists a wealth of information concerning the daily activities of the Sumerians.

Eridu, ceremonially being the oldest Mesopotamia city, still isn't well understood by archaeologists. It was originally excavated in 1854 by J. H. Taylor for the British Museum. During this early era of archaeology, very little was known about how to properly perform an excavation. Archaeologists were more concerned with finding treasure than discovering history. The first excavation didn't turn up anything, and the site was abadoned.

It was later excavated again in 1918, and in 1919, but still not much was discovered. Finally, in 1946, the Government of Iraq held the first fruitful excavation of Eridu. At the time, the Iraqi government was concerned with recovering the identity of the Iraqi people pre-muslim times.

The excavators found that the Ziggurat at Eridu had been built on top of older structures. In fact, the site of the Ziggurat used to be an old temple. The people of Eridu built an original temple around 4900 BC, and when that temple was no longer usuable, they built another temple on top of the original. Archaeologists have found several temples on the site, each being built over the top of the previous. The Ziggurat was built later, possible as recent as 2100 BC.

Another wonderful picture by Balage Balogh, depicting Enki's boat voyage from Eridu. Enki was the Sumerian god who looked over the Ziggurat at Eridu.