The Urban Plan of Tenochtitlan

Tenochtitlan housed 200,000 inhabitants by the year 1519. The city had been constructed within the lake in an area of freshwater springs, on an oval-shaped island. It had a netlike arrangement of canals and streets crossed by numerous bridges creating clear divisions into different blocks.The sacred precinct lay in the center, housing 78 buildings, notably the main temple dedicated to Huitzilopochtli and Tlaloc, temples to other deities arranged around plazas, schools, the ballcourt, and the skull rack (tzompantli). This area was squared off by a defensive wall adorned with serpent heads. It had three entrances that linked it to the three main avenues. Around this nucleus were arranged the palaces of the rulers and the nobility (with their multiple rooms, ponds, and baths). Further out lay the houses of the leading members of Mexica society, multifamily housing, and finally the agricultural population on the chinampas. The land belonging to the nobles lay outside the city.

The division of Tenochtitlan into four sectors is a reflection of the ancient Mesoamerican tradition of constructing cities on a cosmological basis. The four cardinal points represent the horizontal map of the world: Atzacoalco to the northeast (the modern-day San Sebastián barrio), Cuepopan to the northwest (the Santa María barrio), Zoquiapan to the southeast (the barrio of San Pablo), and Moyotlan to the southwest (the San Juan barrio). The Templo Mayor (Great Temple) also represented the vertical axis of the cosmos with an underworld, a terrestrial level, and a celestial world.

Tlatelolco, the twin city of the Mexica capital, had a rectangular precinct to the east of which lay the great market, which was famous as a center for the distribution of goods from diverse regions of Mesoamerica. It was an open space surrounded by stores, from which seeds, flowers, dogs, birds, slaves, gold, feathers, and other goods were sold.