While standard historical models suggest that the world's very first cities developed in southern Mesopotamia (modern-day Iraq) at sites like Uruk, excavations at Tell Brak in northeastern Syria have turned this timeline upside down. Dating back to the late 5th and early 4th millennia BCE ( c. 4200–3800 BCE ), Tell Brak is evidence of an independent, massive "northern" urban experiment that grew simultaneously with—or perhaps even earlier than—its southern counterparts. [ TRADITIONAL URUK MODEL