instruction: Who were the Sumerians?
output: The Sumerian culture (3000-2350 BC) is regarded as humanity's first urban civilization. It originated in southern Mesopotamia, between the Tigris and Euphrates rivers, and is related to Neolithic cultures, particularly the Uruk culture. They invented the wheel and writing, had a division of labor-based organization, and were incredible builders. Their Sumerian language is unrelated to any other known language. Sumerian is a cuneiform language, with ideograms, symbols, and abstract forms representing ideas rather than specific words or sounds.