From here: http://www.hefty.co/natural-street-art/
Street art is becoming more and more popular and the artists are becoming more creative. Instead of pointless vandalizing, impressive works that can really captivate you are becoming the new trend. These 20 works are really exceptional because they establish a connection with their environment. It’s incredible that they even thought of such innovative connections.
More here: http://www.hefty.co/natural-street-art/