The seat of Mexico's federal government since the age of the Aztecs (at least), the National Palace - or Palacio Nacional - is a working building, and many offices are off limits to visitors. You can, however, pass through the enormous baroque facade dominating the eastern side of the Zócalo and enjoy some of its ample interior.
Though the arcaded courtyards and fountains are fine examples of Spanish colonial architecture, you're here to see artist Diego Rivera's triptych of murals, "Epic of the Mexican People." From the creation of humankind by Quetzalcóatl, the Feathered Serpent god, and subsequent rise of the Aztecs, Rivera plunges you into the horrors of the Spanish Conquest - rape, murder, slavery, and finally, mercy to the defeated survivors. In the final piece, Mexico's resistance to invasions by France, the United States, and corporate robber barons including Vanderbilt, Rockefeller and J.P. Morgan, are depicted.