Mexico's major contribution to the art of the 20th century, murals were originally commissioned in the wake of the Mexican Revolution by the enlightened education minister, Vasconelos.

No better place in Mexico City to start, then, than at the Secretaria de Educación Pública: murals by Diego Rivera and others. Other places to visit nearby are the  Antiguo Convento San Idelfonso , the Palacio Nacional (Rivera's great series on Mexican history) and the Palacio de Bellas Artes (all three of the Tres Grandes, Rivera, Siqueiros and Orozco, plus members of the second generation like Rufino Tamayo). Further afield there are works by Orozco and Siqueiros in the National History Museum in Chapultepec Castle. Across in Polanco, you can visit Siqueiros's own home/studio which he decorated himself. It's then worth heading down Insurgentes to see the mosaic by Rivera on the exterior of the Teatro de los Insurgentes and Siqueiros's Polyforum in Parque de Lama. 

These are just a few of the murals accessible to the public. For a more complete list click here.