Xico is a city in the State of Mexico, Mexico. It serves as the municipal seat of Valle de Chalco municipality, with which it is, for all practical purposes, coterminous. The municipality lies adjacent to the east side of the Federal District and is part of the Mexico City metropolitan area. The city and municipality lie on the old lakebed of Lake Chalco, which was drained like much of the Basin of Mexico. The city name comes from the nearby Xico hill and the name of the municipality comes from the old lake plus a reference to the "Programa Nacional de Solidaridad" which was initiated here. The municipality's glyph and shield make reference to both names. It is a distinct entity from the city and municipality of Chalco, which is nearby. "Chalco" in both names refers to the Chalca tribe that were one of the original inhabitants of the area.