Tenochtitlan was the capital city of the Aztec Empire located on an island in Lake Texcoco, with over 200,000 residents making it one of the largest cities in the world at the time. The Aztecs built the city according to an ancient prophecy, constructing buildings and infrastructure on reclaimed land around the lake. The highly advanced Aztec culture practiced human sacrifice by ripping out still-beating hearts and throwing bodies down temple stairs as offerings to their gods.