Lake Texcoco was a natural lake within the Anáhuac or Valley of Mexico. Lake Texcoco is best known as where the Aztecs built the city of Tenochtitlan, which was located on an island within the lake. After the Spanish conquest of the Aztec Empire, efforts to control flooding by the Spanish led to most of the lake being drained. The entire lake basin is now almost completely occupied by Mexico City, the capital of the present-day nation of Mexico.