There are a number of ancient civilizations that could be considered the oldest in the world, but one of the most notable is the Sumerian civilization. The Sumerians were a people who lived in Mesopotamia, the region between the Tigris and Euphrates rivers, from around 5500 BC until the rise of the Babylonian Empire in the early second millennium BC. They were the first people to invent writing, a system of mathematics, and the wheel. Their civilization was also one of the first to have cities, temples, and a complex social structure.
