The ancient Sumerians established one of the world's first civilizations in the Mesopotamian valley, primarily located between the Tigris and Euphrates rivers. This region, particularly in modern-day Iraq, showcased advanced societal developments, including the creation of city-states like Uruk and Ur, innovations in writing (cuneiform), and advancements in agriculture, mathematics, and trade. The Sumerians are often credited with laying the foundational aspects of civilization, such as organized religion and government. Their contributions significantly influenced subsequent cultures in the region, making Mesopotamia one of history's cradles of civilization.