Teotihuacan (Mexico)

Ancient city with astronomical alignments and mica in its pyramids; cited in ancient-astronaut theory.

Teotihuacan (; Spanish: Teotihuacán, Spanish pronunciation: [teotiwaˈkan] ; Classical Nahuatl: Teōtīhuacān, Classical Nahuatl pronunciation: [te.oːtiːˈwakaːn] ) is an ancient Mesoamerican city located in a sub-valley of the Valley of Mexico, which is located in the State of Mexico, 40 kilometers (25 mi) northeast of modern-day Mexico City. Teotihuacan is known today as the site of many of the most architecturally significant Mesoamerican pyramids built in the pre-Columbian Americas, namely the Pyramid of the Sun and the Pyramid of the Moon. Although close to Mexico City, Teotihuacan was not a Mexica (i.e. Aztec) city, and it predates the Aztec Empire by many centuries. At its zenith, perhaps in the first half of the first millennium (1 CE to 500 CE), Teotihuacan was the largest city in the Americas. Its population has been estimated to be at least 25,000, but likely sat around 100,000 during its height, potentially making it the sixth-largest city in the world during its epoch. The city covered eight square miles (21 km2) and 80 to 90 percent of the total population of the valley resided in Teotihuacan. Apart from the pyramids, Teotihuacan is also anthropologically significant for its complex, multi-family residential compounds, the Avenue of the Dead, and its vibrant, well-preserved murals. Additionally, Teotihuacan exported fine obsidian tools found throughout Mesoamerica. The city is thought to have been established around 100 BCE, with major monuments continuously under construction until about 250 CE.