Teotihuacán, the capital city of an unknown people who dominated central Mexico from about 200 B.C. to about 700 A.D. Teotihuacán was one of the largest cities of the New World. At its height in about 300 A.D. the city had an estimated population of 85,000 and covered some nine square miles (23 km 2 ). The learning and skills of its inhabitants spread throughout Mexico and laid the foundation for the later Toltec and Aztec civilizations.

Teotihuacán's most impressive structures were the massive Pyramid of the Sun, 213 feet (65 m) high and measuring about 730 feet (223 m) at the base, and the smaller Pyramid of the Moon. In about 700 A.D. the city was destroyed by fire and abandoned. The prestige of Teotihuacán was so great that for centuries its ruins were considered sacred and were the object of frequent pilgrimages. The ruins are about 20 miles (32 km) northeast of Mexico City.