Xaltocan was a pre-Columbian city-state and island situated in the center of Lake Xaltocan. This lake was part of an interconnected shallow water system that included Lake Texcoco in the Valley of Mexico. The site is currently located within the village of San Miguel Jaltocan in Nextlalpan, State of Mexico.
Originally settled by the Otomi people, the island was vacated following a late fourteenth-century war where an alliance of Tepanecs and Mexica defeated the Otomi. The displaced population was relocated to areas including Otumba, Metztitlan, and Tlaxcala, after which Xaltocan was resettled by Nahuatl speakers. In the Nahuatl language, the name for the site can be translated as either "sandy ground of spiders" or "where it is planted on the sand."