“The city represented a new degree of human concentration, a new magnitude in settlement. The ancient city of Ur, the early home of Abraham, with its canal, harbors, and temples, occupied 220 acres, while the walls of Uruk encompassed an area of just over two square miles. Khorsabad, about 700 B.C., enclosed some 740 acres; Nineveh, a century later, perhaps 1,800 acres; while later still, Babylon, before its destruction by the Persians, was surrounded by at least eleven miles of walls.
What is harder to estimate is the population of these ancient towns. They were at first limited by the same difficulties in transport as early medieval Western towns, and seem to have had populations of the same order, that is, from about two thousand to twenty thousand people. Probably the normal size of an early city was close to what we would now call a neighborhood unit: five thousand souls or less.
Frankfort, digging in Ur, Eshnunna, and Khafaje, which flourished about 2,000 B.C., found that the houses numbered about twenty to the acre, which gave a density, he calculated, of from 120 to 200 people per acre, a density certainly in excess of what was hygienically desirable, but no worse than that of the more crowded workmen’s quarters in Amsterdam in the seventeenth century: in both cases perhaps offset a little by the presence of canals.”
“The City In History,” Lewis Mumford, Horizon, July, 1961, Volume III, Number 6
Ruins in the Town of Ur, Southern Iraq, 2006, Photograph: M. Lubinski.