The heart of Mexico City is the historic Plaza de la Constitución, colloquially called the Zócalo. It’s the second-largest public square in the world after Moscow’s Red Square and the site of festivals, events, protests, and home to some of Mexico’s most cherished sites. Forming the east side of the Zócalo is the Palacio Nacional (National Palace), the seat of the Mexican federal government. The Palacio was built using materials from the original Aztec palace that existed on the site pre-conquest, and features a spectacular mural by the famed Mexican painter Diego Rivera depicting a thousand years of Mexican history. On the north side of the plaza sits the Catedral Metropolitana, an enormous cathedral built over the course of 250 years.
Just off the square is the excavation site of the Templo Mayor (Grand Temple) dedicated to the Aztec gods of rain and war, and destroyed the conquistadors in 1521. The adjoining museum displays artifacts that have been excavated from the site since it was discovered in 1978.