Eridu, pictured here in Balage's wonderful reconstruction, was considered by the Sumerians
to be the most ancient city. According to the legend of creation found at Sippar, Eridu was
the first city to be created when all the land was sea.

Digging at Abu Shahrain, the site of the ancient Temple of Eridu, excavators have been able to
note that the temple had been rebuilt and expanded many times in antiquity, and they have
succeeded in examining some of its earliest forms (a simple four wall enclosure, dating to the 5th
mill . BC), to some of its last reconstructions in the late Sumerian period. At the below url is a
site which admirably breaks down the archaelogical findings for us:

http://babel.massart.edu/~tkelley/v5.0/eridu/

We can see that Balage has used temple layer 6 of mound 1 as his Eridu temple painting, this being the temple at about its most developed and elaborate stage. Interestingly, excavators have found fish bones throughout the complex at this level, and this attests to ancient accounting of Eridu as close by the Persian gulf (although today, centuries of build-up now have it miles and miles from the coast.) Because the bones were found at the top of the temple amidst the inner sanctum, one can infer that they were offered in some ritualized fashion to Enki, and this formed part of the proceedings of his cult. The following description is from the notes on layer 6 from the url above:"Around the ashes laying on the floor around the podium were fish bones. Throughout the northeastern end of the sanctuary were large quantities of fish and small animal bones, and around where the walls were worn and replastered, beneath the plaster and into the actual brickwork."