In many cities around the world, street artists are relegated to abandoned buildings in dilapidated sections of the city. However, Mexico City has a rich tradition of public murals by famous artists such as Diego Rivera. The city was able to allow these artists to use some of the prime real estate as a canvas to display their creations.
Here is a video on "All City Canvas":
Reference: Jaime Rojo and Steven Harrington, Mexico City: High Art in Thin Air, HuffingtonPost.com, May 16, 2012