Built some 2000 years ago by highly skilled people, the ceremonial and urban center 44 km. northeast of Mexico City spreads over 20 square km – a vast agregation of shrines, temples, priestly palaces, pyramids, and appartments devided by the Street of the Dead. Five hundred years after Christ, this street served as the main ceremomial artery of a city of 4000 buildings and perhaps 100 000 inhabitants. Some archeologists think its construction kept 10000 laborers busy for 20 years. Teotihuacan lingeres as a minor Aztec religious center untl the Spaniards arrived, then became completely overgrown. Scholars knew of its existence, but formal excavation did not begin until the end of the 19th century.