The grand national palace was initiated by Cortés on the site of Moctezuma's home and remodeled by the viceroys. Its current form dates from 1693, although a third floor was added in 1926. Now the seat of government, it has always served as a public-function site.
Diego Rivera's sweeping epic murals on the second floor of the main courtyard exert a mesmeric pull and are the real reason to visit. For more than 20 years, starting in 1929, Rivera and his assistants mounted scaffolds day and night, perfecting techniques adapted from Renaissance Italian fresco painting. The result, nearly 1,200 square feet of vividly painted wall space, is grandiosely titled Epica del Pueblo Mexicano en su Lucha por la Libertad y la Independencia (Epic of the Mexican People in Their Struggle for Freedom and Independence). The paintings represent two millennia of Mexican history, filtered through Rivera's imagination. He painted pre-Hispanic times in innocent, almost sugary scenes of Tenochtitlán.
Only a few vignettes—a man offering a human arm for sale, and the carnage of warriors—acknowledge the darker aspects of ancient life. As you walk around, you'll pass images of the savagery of the conquest and the hypocrisy of the Spanish priests, the noble independence movement, and the bloody revolution. Marx appears amid scenes of class struggle, toiling workers, industrialization (which Rivera idealized), bourgeois decadence, and nuclear holocaust. These are among Rivera's finest works—as well as the most accessible and probably most visited. The palace also houses a minor museum that focuses on 19th-century president Benito Juárez and the Mexican Congress.
The liberty bell rung by Padre Hidalgo to proclaim independence in 1810 hangs high on the central facade. It chimes every eve of September 16th, while from the balcony the president repeats the historic shout of independence to throngs of citizens below. As a working seat of government, the Palacio Nacional is remarkably accessible, but it can be closed with little notice.