Greater Mexico City

Greater Mexico City refers to the conurbation around Mexico City, officially called Mexico City Metropolitan Area (Zona Metropolitana del Valle de México), constituted by Mexico City itself composed of 16 Municipalities—and 41 adjacent municipalities of the states of Mexico and Hidalgo. For normative purposes, however, Greater Mexico City most commonly refers to the Metropolitan Area of the Valley of Mexico (Zona Metropolitana del Valle de México) an agglomeration that incorporates 18 additional municipalities. As of 2010 Census, Greater Mexico City had a population just over 20 million, making it the largest metropolitan area in North America just ahead of the New York metropolitan area. But as of a 2014 census, it's estimated the population of Greater Mexico City was 25.4 million people, making it the largest urban agglomeration in the western hemisphere. It is surrounded by thin strips of highlands which separate it from other adjacent metropolitan areas, of which the biggest are Puebla, Toluca, and Cuernavaca-Cuautla, and together with which it makes up the Mexico City megalopolis.

Since the 1940s there have been different proposals to establish the limits of the growing conurbation of Mexico City, and different definitions were used unofficially as the city continued to grow. The Federal Government (represented by the Department of Social Development), the government of Mexico City, and the government of the State of Mexico agreed on the official definitions for both the Mexico City Metropolitan Area and the Metropolitan Area of the Valley of Mexico on 22 December 2005. Per the agreement, most urban planning projects will be administered by Metropolitan Commissions.

Starting 2016, On January 29, Mexico City proper ceased to be called the Federal District (Spanish: "Distrito Federal" or D.F.) and is now in transition to become the country's 32nd federal entity called officially "City of Mexico" (Spanish: "Ciudad de Mexico" or CDMX), giving it a level of autonomy comparable to that of a state. Because of a clause in the Mexican Constitution, however, as the seat of the powers of the federation, it can never become a state, lest the capital of the country be relocated elsewhere. The English name "Mexico City" remains. Its original 16 "Boroughs" became "municipalities".

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