Fifteen hundred years ago, Teotihuacan was already known the length and breadth of Mesoamerica. Every traveler to the Valley of Mexico would take time to visit the great city, if only to admire its brightly painted public buildings and stroll down the wide and imposing Street of the Dead that traversed the city's center. Teotihuacan was the largest human settlement in the Americas, with a population of at least 100,000 people.