California's Matilija Dam is a huge mistake. Over 60 years after its construction, engineers and ecologists are realising it does more harm than good — a feeling shared by the rogue artists who painted huge, easy instructions as a fix.
I'm not sure what the proper protocol is for removing a dam without causing an instant flood, but it's probably a little more complicated than splitting it down the middle. Still, the work's been a hit with locals. Even the county public works director wants the graffiti to stay: "Everyone I've talked to has really enjoyed it. It sends a good message." [LA Times]
Image: Mel Melcon/Los Angeles Times