page_title: Mexico City
section_title: Environment
hierarchical_section_title: Mexico City / Geography / Environment
caption_attribution_description: Trajineras in Xochimilco
context_page_description: Mexico City is the capital and largest city of Mexico and the most-populous city in North America. Mexico City is one of the most important cultural and financial centres in the world. It is located in the Valley of Mexico, a large valley in the high plateaus in the center of Mexico, at an altitude of 2,240 meters. The city has 16 subdivisions, formerly known as boroughs.
  The 2009 population for the city proper was approximately 8.84 million people, with a land area of 1,485 square kilometers. According to the most recent definition agreed upon by the federal and state governments, the population of Greater Mexico City is 21.3 million, which makes it the second largest metropolitan area of the Western Hemisphere, the eleventh-largest agglomeration, and the largest Spanish-speaking city in the world.
  Greater Mexico City has a GDP of $411 billion in 2011, making Greater Mexico City one of the most productive urban areas in the world. The city was responsible for generating 15.8% of Mexico's GDP, and the metropolitan area accounted for about 22% of total national GDP.
context_section_description: Originally much of the valley lay beneath the waters of Lake Texcoco, a system of interconnected salt and freshwater lakes. The Aztecs built dikes to separate the fresh water used to raise crops in chinampas and to prevent recurrent floods. These dikes were destroyed during the siege of Tenochtitlan, and during colonial times the Spanish regularly drained the lake to prevent floods. Only a small section of the original lake remains, located outside Mexico City, in the municipality of Atenco, State of Mexico.
  Architects Teodoro González de León and Alberto Kalach along with a group of Mexican urbanists, engineers and biologists have developed the project plan for Recovering the City of Lakes. If approved by the government the project will contribute to the supply of water from natural sources to the Valley of Mexico, the creation of new natural spaces, a great improvement in air quality, and greater population establishment planning.
caption: Trajineras in the canals of Xochimilco. Xochimilco and the historic center of Mexico City were declared a World Heritage Site in 1987.
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