Technotitlán held for the Aztecs an imperial mythos and centrality not unlike that of ancient Rome. According to Aztec myth, the "Mexicas" (as the Aztecs referred to themselves) were once a nomadic tribe that survived by hunting, fishing and gathering. They were prompted to move to the Valley of Mexico by Huitzilopochtli, "Hummingbird-on-the-left," the god of war. Huitzilopochtli, the legend goes, ordered the Mexica to take over the world and directed them to central Mexico. When they reached Lake Texcoco, they spied a golden eagle atop a prickly-pear cactus, devouring a snake - it was a sign that they should found their city here.

Cortés described Technotitlán to the King of Spain in the first of a series of letters:

The great city of Temixtitan is built on the salt lake, and no matter by what road you travel, there are two leagues from the main body of the city to the mainland. There are four artificial causeways leading to it, and each is as wide as two cavlary lances. The city itself is as big as Seville or Cósa. The main streets are very wide and very straight; some of these are on the land, but the rest and all the smaller ones are half on land, half canals where they paddle their canoes. All the streets have openings in place so that the water may pass from one canal to another. Over all these openings, and some of them are very wide, there are bridges made of long and wide beams joined together very firmly and so well made that on some of them ten horsemen may ride abreast.

The city has many squares where trading is done and markets are held continuously. There is also one square twice as big as that of Salamanca, with arcades all around, where more than 60,000 come each day to buy and sell, and where every kind of merchandise produced in these lands is found; provisions as well as ornaments of gold and silver, lead, brass, copper, tin, stones, shells, bones and feathers.