Uruk

One of the world's earliest major cities, located in modern Muthanna Governorate, Iraq. Settled from the Ubaid period (before 5000 BC), Uruk rose to dominance c. 3800 BC and by 3100 BC may have housed 40,000 residents across 5.5 sq km. Two great temple complexes -- the Anu Ziggurat with its White Temple and the Eanna sanctuary dedicated to Ishtar -- dominated the city. Proto-cuneiform clay tablets discovered here, dating to c. 3300 BC, represent some of the earliest known writing. Legend credits Gilgamesh with building its 10 km city walls.