Uruk, located in ancient Mesopotamia, was the world's first major city, emerging around 3600-2600 BCE and known for its innovations such as social hierarchies, specialized occupations, and early writing (cuneiform). At its height, Uruk housed 50,000-80,000 inhabitants, with a complex social structure dominated by priests and later kings, and its people produced significant literary works, including the Epic of Gilgamesh. Despite its advancements, Uruk faced decline due to environmental factors and warfare, ultimately leading to its abandonment by 300 CE.