Great Ziggurat of Ur

A massive stepped temple platform built for the moon god Nanna around 2100 BC, its three great stairways meeting at the front.

A ziggurat is a stepped tower with a temple on top, and it was the most distinctive kind of building in ancient Mesopotamia, the land between the Tigris and Euphrates rivers. Ur's ziggurat is one of the best preserved in the region. Its base measures about 64 by 45 metres, and it may once have stood around 30 metres tall, so it would have been the highest point in the city and visible for miles across the flat land.

How it was built

The core of the ziggurat is a solid mass of mud brick, sun-dried bricks made of clay. It was covered with a tougher skin of baked bricks stuck together with bitumen, a natural tar. The lowest level alone may have used about 720,000 baked bricks, some weighing up to 15 kilograms each. The builders were clever: they left small holes through the outer layer so water could dry out of the damp core, and they built drains on the terraces to carry away winter rain.

What it was for

Three huge staircases led up to a gateway on the first terrace. From there more steps climbed to a temple for Nanna at the very top. The ziggurat stood inside a temple complex that also worked as the city's centre of government. People probably brought extra crops there as offerings and received their regular food rations, so a visit fed both the spirit and the stomach. The top temple has not survived.

Ruins and rebuilding

By the 6th century BC the ziggurat had crumbled, and Nabonidus, the last king of Babylon, rebuilt its upper levels. In the 1920s and early 1930s the archaeologist Sir Leonard Woolley, working for the University of Pennsylvania Museum and the British Museum, uncovered it fully. In the 1980s the front wall of the lowest level and the three great staircases were rebuilt, which is why that part looks so neat today. The site was damaged during the 1991 Gulf War, and bullet holes can still be seen in its walls.

On the globe

The model shows the massive stepped platform built for the moon god Nanna, with its three great stairways meeting at the front. Zoom in to follow the staircases up to the gateway on the first terrace.