Valley of Mexico

The Valley of Mexico (Spanish: Valle de México; Nahuatl languages: Anahuac, lit. 'Land Between the Waters'), sometimes also called the Basin of Mexico, is a large natural basin on the highland plateau of central Mexico. Surrounded by mountains and volcanoes, the valley was the historical center of several pre-Columbian civilizations including Teotihuacan, the Toltec, and the Aztec Empire, and today is almost entirely occupied by Mexico City, the capital of the modern nation of Mexico.

A natural endorheic basin, the Valley of Mexico historically contained five shallow, interconnected lakes called Lake Zumpango, Lake Xaltocan (Nahuatl languages: Xāltocān), Lake Xochimilco, Lake Chalco, and the largest, Lake Texcoco, which at their greatest extent together covered about 1,500 square kilometers (580 sq mi) of the valley floor. When Spanish explorers first arrived in the Valley of Mexico in 1519, it had one of the highest population concentrations in the world with about one million people. After the conquest of the Aztec Empire, the Spaniards rebuilt the largest and most dominant city, Mēxihco Tenōchtitlan, renaming it Ciudad de México (Mexico City) and over time began to drain the lakes' waters to control flooding. By the 20th century the lakes had almost entirely disappeared and the municipalities of Mexico City eventually grew to occupy the reclaimed land of the former lakebed.

The Valley of Mexico is located in the Trans-Mexican Volcanic Belt. The valley contains most of the Mexico City metropolitan area, as well as parts of the State of Mexico, Hidalgo, Tlaxcala, and Puebla. It is approximately 125 km (78 miles) long and 75 km (47 miles) wide with a NNE-SSW orientation, covering a total surface area of approximately 9,600 km2 (3,700 sq mi). The Valley of Mexico can be subdivided into four basins, but the largest and most studied is the area that contains Mexico City.