Teotihuacan

Teotihuacan is the ruin of a vast ancient city in a side valley of the Valley of Mexico, about 40 kilometres north-east of modern Mexico City. Founded around the second or first century BCE, it grew into one of the largest cities in the world of its time, laid out around the Avenue of the Dead and the great Pyramids of the Sun and the Moon. Its influence reached across Mesoamerica, yet the name of the city in its own language, and even the language its people spoke, remain uncertain.

Small farming villages were scattered across the valley from around 600 BCE. In the last two centuries BCE people began to gather around the springs at Teotihuacan, and the settlement took on an urban form; the most commonly cited founding date is about 100 BCE. Volcanic eruptions further south, among them the eruption of Xitle near the rival centre of Cuicuilco, may have sent refugees into the valley. The population then grew fast, perhaps to 60,000 or more within the first century and a half CE.

The Pyramid of the Sun, about 65 metres high, was completed by around 100 CE. To the south, inside a vast enclosure called the Ciudadela, stood the Temple of the Feathered Serpent, decorated with carved serpent heads. Around 300 CE that temple was defaced, and building activity shifted towards large stone apartment compounds for ordinary residents.

Between about 350 and 550 CE the city was at its peak, with some 2,000 buildings across roughly 18 square kilometres. Population estimates range widely, from 50,000 to 250,000, with recent studies of housing favouring about 100,000. Teotihuacan was multi-ethnic: whole neighbourhoods were occupied by migrants, such as people from Oaxaca who kept Zapotec-style customs, and traders from the Gulf Coast who built round adobe houses. Whether the dominant group spoke a Nahua, Otomi, Totonac or other language is unresolved.

The city's reach is clearest in the Maya lowlands. In 378 CE a warlord linked to Teotihuacan, Sihyaj K'ahk', took control of Tikal, an event recorded on Maya monuments, and the city's distinctive talud-tablero style of stepped platforms was widely copied in the Maya region. Historians still debate whether this reflects military domination or the prestige of a distant power.

Around 550 CE the city's major monuments were sacked and burned. An older view blamed foreign invaders; more recent research notes that the fire was largely limited to elite and civic buildings and finds no clear sign of an outside attack, so internal revolt is now often proposed. Drought and famine may also have played a part: a series of climatic disasters in 535 and 536 has been linked to the eruption of Ilopango in El Salvador, and skeletons of sixth-century children show signs of malnutrition. The city lost its power in the following two centuries, although people continued to live there in smaller numbers.

Nahua-speaking settlers moved into the area in the thirteenth century. The Aztecs regarded the ruins with awe and gave them the name Teotihuacan, usually translated as the place where the gods were born, though this reading has been questioned. In the fifteenth century the local town was a tributary of Azcapotzalco and later of the Acolhua of Texcoco. After the Spanish conquest, a colonial report of 1580 found that Nahuatl was the main language spoken there, alongside Otomi.

The scholar Carlos de Sigüenza y Góngora dug around the Pyramid of the Sun in the late seventeenth century. From 1905 Leopoldo Batres led a large excavation and restoration for the government of Porfirio Díaz, finishing the Pyramid of the Sun for the centenary of independence in 1910. Manuel Gamio worked at the Ciudadela in the 1920s, and Mexico's national institute of anthropology and history carried out site-wide restoration from 1960 to 1965. In 2003 archaeologists discovered a tunnel running under the Temple of the Feathered Serpent, apparently sealed around 200 CE, which has since yielded tens of thousands of objects, including pools of liquid mercury.

UNESCO listed Teotihuacan as a World Heritage Site in 1987. Development has repeatedly threatened its edges, from a supermarket permitted in an outer archaeological zone in 2004 to bulldozing for an amusement park in 2021, when federal forces were sent to stop the work. In 2024 it was the second most visited archaeological sites in Mexico.