Teotihuacan
Teotihuacan grew into one of the largest cities in the world — perhaps 125,000 people — laid out on a rigid grid around a three-mile avenue and pyramids visible for miles. Its residents lived in multi-family apartment compounds, unusual anywhere in the ancient world, and neighborhoods housed foreign merchants from Oaxaca and the Maya lands. It burned around 550 CE, its temples deliberately destroyed, possibly from within. We do not know what its people called themselves or what language they spoke.
A durable new order — a state, an institution, a system of rule — is deliberately built and consolidated, outlasting the people who founded it.