Tenochtitlan: The Aztec Capital on Lake Texcoco

Tenochtitlan was located on several islands in the western part of Lake Texcoco, which lies in the Valley of Mexico at an altitude of about 2240 meters. To the north, east and south, the valley is surrounded by a mountain range dominated by the volcanoes Popocatépetl and Iztaccíhuatl. The city was connected to the mainland by five causeways to the north, west, and south. On a neighboring island to the north, separated from Tenochtitlan only by a canal, was the initially still independent city of Tlatelolco.

Today, Lake Texcoco no longer exists in its former extent, as it was gradually drained by the Spanish. Only in Xochimilco, south of today's Mexico City, small bodies of water form a last remnant of the lake.

The islands on which Tenochtitlan and Tlatelolco were located occupied a total area of about 13 square kilometers. The city was connected to the mainland by five causeways built of stone and earth. They had several breaks, which were closed by movable wooden bridges. The Aztecs took advantage of this fact, especially in 1521, when they defended their city against the Spanish. Since Tenochtitlan could only be reached by causeways and by sea, it had no city walls.

Coming from the north, west and south, the causeways converged on the large marketplace of Tlatelolco and the square in front of the Templo Mayor in Tenochtitlan. This formed the center of the city. Around the square were built the palaces of the rulers Moctezuma I, Axayacatl and Moctezuma II during the history of the Aztecs. The main streets, running at right angles to each other, simultaneously divided Tenochtitlan into the four districts of Moyotlan, Zoquiapan, Atzacualco, and Cuepopan, which in turn were divided into smaller districts. Traffic within the city moved along a maze of alleys and canals. For trade with other settlements, in addition to the causeways, the port in eastern Tenochtitlan was used.

The often multi-storey dwellings of the lower social classes were densely packed; some of them were built on stilts. The residential properties, especially in the outer parts of the city, often had a fenced garden. Behind them were the so-called chinampas, fields that were often only a few meters wide but very long in relation to their width. The chinampas were cultivated areas obtained from the swampy soil, and their favorable soil moisture often made it possible to have several harvests a year. Nevertheless, the chinampas alone were not sufficient to feed Tenochtitlan's ever-growing population. Moreover, as the city and the Aztec empire expanded, land ownership became more and more a privilege of the nobility. However, the proportion of the higher classes in the population was relatively high. 

An outstanding importance took the extensive temple district. Around the Templo Mayor, several larger and smaller temples were grouped, which were dedicated to various deities and certain cults of individual social classes. Furthermore, there was a specially created place for the ritual ball game in the temple district.

The northern part of the city was formed by the city of Tlatelolco, which was independent until 1473. The settlement had already been closely linked to Tenochtitlan before its conquest and had been an economic center of the region. After its subjugation by the inhabitants of Tenochtitlan, Tlatelolco largely retained this character; even the Spaniards were impressed by the size and variety of goods in Tlatelolco's market.  In all, when the Spaniards arrived, the two now-united cities may have been home to tens of thousands of people, possibly more than 150,000, making Tenochtitlan one of the largest cities in the world at the time.