While I was in Miami, I had to check out the Wynwood Walls which is located in the Wynwood neighborhood just north of Downtown. In 2009, developer Tony Goldman had the idea to turn the large windowless buildings into to blank canvases and invite the best street artist in the world to paint on them. Since then, 100s of murals have been added to the area. I saw work by Retna, Kenny Scharf, Shepard Fairey, and Nuezz to just name a few. You can check out their website here and they have an ap which is worth getting when you go.