A city’s walls were far more than a boundary to enclose a settlement: they protected those within from would-be aggressors. Defensive walls were first seen in Mesopotamia around 3000BC, when inter-city conflict increased the need for protection. Walls were seen as iconic structures directly linked to the power of the city’s god. They were often vast and complex structures. The walls of Babylon boasted a corridor-like chamber, separated by over 100 bronze gates, which ran its entire length and was wide enough to give passage to a four-horse chariot.
