The civilization that built Teotihuacan is unknown. Archaeologists know that the city was created by a sophisticated Mesoamerican society, but no surviving record identifies the people by a confirmed historical name.
Teotihuacan developed northeast of present-day Mexico City and reached its height between about 100 BCE and 550 CE. Its monumental center includes the Pyramid of the Sun, the Pyramid of the Moon, the Avenue of the Dead, and the Temple of the Feathered Serpent. At its peak, the city may have had more than 100,000 inhabitants, making it one of the largest cities in the ancient Americas.
The Aztecs encountered the abandoned city centuries later and called it Teotihuacan, a Nahuatl name usually translated as “the place where the gods were created.” That later name does not prove that the Aztecs built it. Maya inscriptions and art indicate contact between Teotihuacan and Maya cities, but neither the Maya nor the Aztecs can be identified as its builders. The city’s original name is also unknown.