What Is a Ziggurat? A Mountain Built Where There Are None

A ziggurat is a solid stepped mass, not a hollow building, which is the detail most often misunderstood. The core is mud brick dried in the sun, cheap and quick to make from the river clay that is the region's only abundant material, faced with a skin of kiln-fired brick set in bitumen, which is far more durable and expensive and is what took the weather. Layers of reed matting were laid at intervals through the core to bind it, and weeper holes were built in to let moisture escape, because a solid mud mass with no drainage would swell and slump. Access was by monumental staircases, typically three converging on the first terrace, and successive terraces stepped inward. At the top stood a small shrine, and the whole thing was the platform for it. Sizes varied considerably, with the best-preserved example at Ur reconstructed to a first terrace of around thirty by forty-five metres, and the structure at Babylon, known from texts and foundations rather than standing remains, considerably larger.

The religious logic followed from the idea that a god had a physical dwelling in the city and needed a place to descend from the sky and be received. The high shrine was that meeting point, restricted to priests, and the working temple where offerings were prepared, where the god's statue was fed and clothed daily and where the institutional business went on sat at ground level in the complex around the base. That complex was the economic centre of the city as much as the religious one, holding land, employing large numbers, storing grain, lending and keeping accounts, which is why so many of the earliest cuneiform tablets are temple administrative records. Building a ziggurat was therefore a statement about a ruler's relationship with a god and a demonstration of the labour a city could command, and kings recorded their construction and repair of them in inscriptions placed where later restorers would find them, which is how the sequence of builders is known.

Around two dozen have been identified across Mesopotamia and Iran, and a few stand out:

• •The Great Ziggurat of Ur, built under Ur-Nammu around 2100 BCE, dedicated to the moon god Nanna, whose lowest stage and staircases were reconstructed in the twentieth century and which is the image most people picture
• •Chogha Zanbil in Iran, an Elamite structure from around 1250 BCE, the best preserved of all, which was never finished and was buried and therefore protected
• •Etemenanki at Babylon, dedicated to Marduk, whose name means the foundation of heaven and earth, known from a detailed tablet describing its dimensions and almost entirely demolished in antiquity
• •Structures at Uruk, Nippur, Eridu, Ashur and Dur-Sharrukin among others, spanning the Sumerian, Babylonian and Assyrian periods
• •Later Assyrian examples experimented with a continuous spiral ramp rather than stepped terraces, an arrangement echoed much later in the spiral minaret at Samarra
• •None of them is a pyramid in the Egyptian sense, since an Egyptian pyramid is a tomb with internal chambers while a ziggurat is a solid platform for a building on top

The biblical account of a tower built to reach heaven, abandoned when its builders' language was confused, is generally connected by scholars to Etemenanki at Babylon, and the connection makes sense of several details. The story describes building with brick and bitumen rather than stone and mortar, which is precisely the Mesopotamian method and would have been noteworthy to a writer from a stone-building region. The name Babel is Babylon, and the Hebrew text plays on a verb meaning to confuse. Etemenanki was repeatedly damaged, rebuilt and finally demolished, with Alexander reportedly intending to restore it and clearing the rubble before his death. The story has been read as an explanation of linguistic diversity, as a critique of imperial hubris and, by several commentators, as a response by a subject people to the overwhelming scale of the imperial capital that had deported them, which would make the tower a real building seen from the outside and reinterpreted rather than a fictional one.

A ziggurat is a solid stepped platform of sun-dried mud brick faced in kiln-fired brick set in bitumen, with reed matting for binding and weeper holes for drainage, built where a flat plain offered no stone and no high ground. It was not entered: the shrine on top was a place for a god to descend, while the working temple and the city's economic administration operated at ground level. Around two dozen are known, the best preserved being Chogha Zanbil, and Etemenanki at Babylon is the likely tower of Babel.