Every Spanish colonial city in North America was laid out according to a textbook plan, with a plaza at the center surrounded by a church, government buildings, and military headquarters. Because Mexico City was the capital of New Spain, its zócalo is one of the grandest, graced on all sides by stately 17th-century buildings. The Plaza de la Constitución, as this square is officially called, is also one of the three biggest public squares in the world.

Zócalo actually means "pedestal" or "plinth." A grand monument to Mexico's independence was planned and the pedestal built, but the project was never completed. Nevertheless, the pedestal became a landmark for visitors, and soon everyone was calling the square the zócalo, even after the pedestal was removed. The square covers almost 4 hectares (10 acres) and is bounded on the north by Cinco de Mayo, on the east by Pino Suárez, on the south by 16 de Septiembre, and on the west by Nacional Monte de Piedad. The downtown district -- especially north of the Templo Mayor, one of the oldest archaeological sites in the city -- is currently undergoing an important restoration project that is renewing much of its colonial charm. Occupying the entire east side of the zócalo is the majestic red tezontle-stone Palacio Nacional, seat of the Mexican national government, and on the northern border is the Catedral Metropolitana.