The Aztecs lived in ancient Mexico for 400 years. They originally moved frequently due to not being welcome as neighbors, as they practiced human sacrifice to please their gods. They eventually settled in the Valley of Mexico, building canoes to fish and trade. The Aztecs established a system of free public schools mandatory for all children, including girls and slaves, to educate the population and train specialists in fields like engineering, medicine, and warfare. As their cities grew, the Aztecs created floating gardens on Lake Texcoco to solve food shortages by growing crops on anchored rafts.