 Erosion has usually reduced the surviving ziggurats to a fraction of their original height, but textual evidence may yet provide more facts about the purpose of these shrines.In the present state of our knowledge it seems reasonable to adopt as a working hypothesis the suggestion that the ziggurats developed out of the earlier temples on platforms and that small shrines stood on the highest stages..." Access to the shrine would have been by a series of ramps on one side of the ziggurat or by a spiral ramp from base to summit.The Mesopotamian ziggurats were not places for public worship or ceremonies.