The Valley of Mexico
was home to some of the most powerful and largest cities that had ever existed in the Pre-Columbian era.

Teotihuacan was the largest and most influential urban center of the Classic era, (300-B.C. to 1000 A.D.). It was at its apex the trade center of the new world, with Teotihuacanos having established trading centers as far south as the Mayan area. Its rule lasted for a millenia, a period longer then that of the Roman Empire.

Tenochtitlan was the Island Capital of the Aztec Empire. The city rose in the Postclassic era (1000 A.D. to 1590 A.D.) after the collapse of the Classic centers. To the Aztecs, Teotihuacan was an ancient city, thought to have been abandoned by giants who had created the city in the dawn of pre-history.

Today Modern Mexico City covers an area that at the time of the Conquest held Lake Texcoco. The Spaniards under Cortes, built their city upon the ruins of Tenochtitlan's sacred precinct. Only a small remnant of the lake exist today, the rest covered by Mexico City, the largest city in the world.