Mexico City is the capital of the United States of Mexico; it is the country's largest urban center, the largest city in Latin America, and the third-largest megacity in the world. Mexico City generally refers to the whole metropolitan area, which not only covers the Federal District (Distrito Federal, or D.F.), but also parts of the states of Mexico and Hidalgo. At the beginning of this century, its metropolitan area stretched over an area of 5,122.86 square kilometers (about 2,000 square miles), of which the Federal District accounted for 28.6 percent, and in 2005, Mexico City had a population of 19,331,365, equivalent to almost 20 percent of the national population. The city sits at an altitude of approximately 2,250 meters and is located within a ...