Not long ago, Sumerians were thought to be the first great fortification builders. For example, a timeline mentions the city of Uruk [Sumerian] as being the first undisputed example of [a] fortified city " in 2,700 B.C. Almost 6,000 years prior to that, a community had constructed five round towers, and it was fairly close to Sumer. The five Neolithic towers were carbon dated back to 9,650 B.C. Read more