The Bronze Age civilization that flourished in the Indus River basin from roughly 3300 to 1300 BCE, encompassing at its peak over a million square kilometers and cities including Mohenjo-daro and Harappa — the largest urban civilization of the ancient world, whose script remains undeciphered and whose collapse remains one of archaeology’s great unsolved questions.
At its height, the Indus Valley Civilization was the largest urban civilization on earth. Its cities had indoor plumbing when London was a marsh. Its trade networks reached Mesopotamia. And then, around 1900 BCE, it began to collapse — and we still cannot read its writing.