The biblical Arach (Gen., x, 10), fifteen miles northwest of Larsa, is at present Warka.
The capital of Sumer during its Heroic Age.
The need for self-defense and irrigation led the ancient Mesopotamian to organize and build canals and walled settlements. After 6000BC the settlements grew, becoming cities by the 4th millennium BC.
One of the oldest and best Mesopotamian settlements was Erech (Uruk) in the south, where mud-brick temples were decorated with fine metalwork and stonework, and growing administrative needs stimulated the invention of a form of writing, cuneiform.
The Sumerians were probably responsible for this early urban culture, which spread north up the Euphrates. Important Sumerian cities, were Eridu, Adab, Isin, Kish, Larsa, Nippur, and Ur.