1. Chinampas

About 1345 the Mexica (migrants from the old Toltec state, often called the Aztec) settled on an island in a marshy region of Lake Texcoco and founded the city that would become their capital-Tenochtitlan, on top of which Spanish conquerors later built Mexico City. Though inconvenient at first, the site offered several advantages. The lake harbored plentiful supplies of fish, frogs, and waterfowl. Moreover, the lake enabled the Mexica to develop the chinampa system of agriculture. The Mexica dredged a rich and fertile muck from the lake’s bottom and built it up into small plots of land known as chinampas. The chinampas consists in building up a number of narrow islands, each averaging some 6 to 10 metres (20 to 35 feet) wide and some 100 to 200 meters (325 to 650 feet) long, using layers of vegetation, dirt, and mud. During the dry season, Cultivators tapped water from canals leading from the lake to their plots, and in the temperate climate, they grew crops of maize, beans, squashes, tomatoes, peppers, and chiles year round. Chinampas were so fertile and productive that cultivators were sometimes able to harvest seven crops per year from their gardens. Finally, the lake served as a natural defense: waters protected Tenochtitlan on all sides, and Mexica warriors patrolled the three causeways that eventually linked their capital to the surrounding mainland. In the end, more than 20,000 acres of chinampas were constructed.