Lake Xochimilco, << `soh` chee MEEL koh, >> was one of four lakes that filled the Valley of Mexico at the time of the Spanish conquest in 1521. The freshwater lakes lay south of the Aztec capital Tenochtitlan, now Mexico City. The lakes were the site of chinampas, fertile islands that the Aztec created by alternating layers of mud and marsh plants. Although chinampas do not float, they are often called floating gardens. These areas still provide vegetables and flowers for Mexico City. Brightly painted boats carry tourists through the canals.