Kültepe Assyrian Tablet (large) The Sumerians are the civilization in the geographical region known as the cradle of civilization, located in the south of Iraq (Southern Mesopotamia ) between 4000 BC – 2000 BC . It is considered the oldest known civilization in the world. The Sumerians laid the foundations of countless civilizations that emerged in Mesopotamia . In addition , writing and astronomy first appeared in the Sumerians in Mesopotamia. The first writing was found by the Sumerians around 3200 BC. Their early writings were based on shapes, that is, they used a shape for every being and event. Cuneiform signs are based on a past caption. Signs expressing a concept are called ideograms. According to the general view in the Sumerian scientific world, it is an isolated language that has no connection with any living language. The Sumerians wrote cuneiform on clay tablets. Therefore, we are lucky that many of these clay tablets have survived to the present day. Because other civilizations found in ancient times wrote their writings on parchment or papyrus, and most of them have not survived.