Landmark 01 / 10

The Ziggurat of Ur

• Dhi Qar, 11 km from Nasiriyah
• c. 2100 BCE · reign of Ur-Nammu
• Base 64 × 45 m · estimated height 30 m

Engineering story

The stepped mass and the rain drain

Why it matters

The soft alluvial ground of the south cannot carry great weight, so the answer was stacked terraces, each smaller than the one below, spreading the load. The walls lean inward at a calculated angle; the core is sun-dried mud brick clad in fired brick, and stepped channels cut into the body carry rainwater out before the walls can saturate.