At its peak in AD 600, the greatest metropolis in the Americas covered an area of 20 square kilometers, had a population of 150,000 an was the sixth largest city in the world. The builders of this extraordinary pre-Columbian center remain unidentified, but centuries later, when the Aztecs found the ruined city, they were so impressed that they named it Teotihuacan, meaning ‘place of the creation of gods.’
The site, some 50 kilometers north-east of modern Mexico City, was already settled in the second century BC. A ritual cave there was seen as the place where both humanity and time first began. Significantly, its entrance aligned to a point on the western horizon where the sun set on 12 August an 29 April. These dates are separated by day counts of 260 and 105 (making 365 days), reflecting Mesoamerica’s ancient system, which intermeshed a 260-day ritual calendar and a 365-day standard calendar into a 52-year period: it took 52 years of 365 days for a given date combination to repeat. The same horizon position is the setting point of the Pleiades, the star cluster that makes its initial annual appearance on the first of two days each year when the noon sun passes directly overhead at the latitude of Teotihuacan.
Around AD 100, an 800-meter-long avenue was laid out northwards from the entrance to the cave, precisely perpendicular to the cave sightline, and aligning perfectly with the notch on the sacred mountain, now known as Cerro Gordo. This ‘Avenue of the Dead’ – as the Aztecs called it, although it contained no tombs – was flanked with temples and ended at the Pyramid of the Moon. Later, the first version of the 63-meter-high Pyramid of the Sun was built over the cave and centered on the same sightline. Between AD 150 and 225 the avenue was extended farther south to a new center, where two enclosures – the Great Compound and the Cuidadela – were constructed. Eastern and western avenues, paralleling the cave’s sightline axis, met here. This was the cosmic crossroads, the sacred center or omphalos of the Teotihuacanos. The Temple of the Feathered Serpent was built within the Cuidadela, and up to 200 people were sacrificed at its dedication ceremony.
The end of Teotihuacan is just as great a mystery as its beginnings. Around AD 700 the city temples were methodically destroyed by fire – precisely when and by whom is not known – but the city’s influence survived and spread beyond what is now Mexico.