Was it necessary to bring in all the other pagan gods?  And where did you get Inanna?

Well, yes, it is necessary, frankly.  It’s part of history, and it makes for great discussions about why they believed what they did–how they came to that understanding.  Nietzsche insinuated that people need a god to whom they can give sacrifices, to whom they can be thankful–so they create one.  If we are to discuss this notion, we must look at it from all sides.

It was in the researching of Sumeria that I discovered the sensual Inanna.  Cities in Sumeria were often dedicated to one god over all others—and indeed this was the case in the ancient city of Erech over which she had divine rulership—thus I made Inanna my city’s primary goddess.  Texts differ on what, exactly, she is the goddess of, but according to the wonderfully translated Inanna: Queen of Heaven and Earth by Diane Wolkstein and Samuel Noah Kramer, Inanna is the Goddess of Love and Procreation, worshipped in a “Sacred Marriage” rite at the New Year’s Festival in the fall.  The reigning monarch “marries” Inanna, and this act ensures the fertility of the soil and the fecundity of the womb.  Naava is Inanna’s substitute, in this case.  Neither Naava nor her family—except Cain—understand the significance of this rite.  Hence the chaotic aftermath.  In later years, the poets continued composing songs for this female goddess, but they sang them to Ishtar, Inanna’s Semitic name.

What exactly was a ziggurat and what was it used for?

One of the outstanding features of a Sumerian city is its ziggurat—the tall, stepped, pyramid-like structure with a temple at the top.  No one knows why the Sumerians built them.  We might surmise they wanted to reach the heavens, where their gods existed.  I discovered the first city of Sumeria, Eridu, had a small one.  In Eridu’s earliest phases—dating back to approximately 5500 B.C.—its ziggurat measured about twelve by fifteen feet.  It was made of mud brick and had a niche made for a god’s statue and a single altar upon which sacrifices were laid.  What a quandary Adam and Eve would be in if confronted with such idolatry!  What would they have made of it?