On my way home from work, I bike across an area of UCSD where the eucalyptus trees are growing big and in between the trees, the art is constantly changing. The graffiti panels had been put up for a few weeks. From time to time, I would see an artist contribute new graffiti painting, on top of what was already there. Here is a view of the art that is there currently.

at UCSD, these boards of graffiti art is constantly changing as peopel contribute their creativity to them