The architecture of Mesopotamia is ancient architecture of the region of the Tigris–Euphrates river system, encompassing several distinct cultures, which includes Sumerians and Akkadians, spanning a period from the 10th millennium BC to the 6th century BC. Among the Mesopotamian architectural accomplishments are the development of urban planning, the courtyard house, and ziggurats. Scribes had the role of architects in drafting and managing construction for the government, nobility, or royalty.