Mexico City , is the Federal District (Distrito Federal), capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole. Mexico City is the country's largest city as well as its most important political, cultural, educational and financial center. As an "alpha" global city Mexico City is one of the most important financial centers in North America. It is located in the Valley of Mexico, a large valley in the high plateaus at the center of Mexico, at an altitude of 2,240 metres (7,350 feet). The city consists of sixteen boroughs. Mexico City has a gross domestic product (GDP) of $390 billion US$ in 2008, making Mexico City the eighth richest city in the World. The city was responsible for generating 21% of Mexico's Gross Domestic Product and the metropolitan area accounted for 34% of total national GDP.