The island capital of the Aztec (Mexica) empire, a planned city of perhaps two hundred thousand people that rose from a lake in the Valley of Mexico, sustained by raised garden plots, causeways, and aqueducts. The Spanish who saw it in 1519 were astonished by its scale; a Spanish-led coalition of Indigenous rivals and enemies of Mexica power, especially Tlaxcalans and others, aided by smallpox, besieged and razed it in 1521. Mexico City was built on its ruins, the lake later drained, so the Aztec capital now lies mostly underground.
In 1519 a few hundred Spaniards climbed a mountain pass and looked down on a white city standing in the middle of a lake, linked to the shore by stone roads and crowded with canoes. Some of them later wrote that they wondered whether they were dreaming. Within two years the city was rubble, drained of its people by siege and disease, and a Spanish town was rising on the wreckage. Today the streets of Mexico City run above it. The Aztec capital was among the largest cities on Earth in its time, and it is now one of the most thoroughly buried. To stand in the modern metropolis is to stand on a drowned city that almost no one was meant to find again.