At first glance I had no idea of what I was looking at on the coast of California. We parked our car and walked up to this man made structure to investigate. Long story short....The was a military bunker (pill-box) on the coastline of CA to watch for any invading boats or planes in WW2. (you can get more information by searching for "pill-box Devil's slide" Of course it is painted with graffiti over the years. Notice how the wind and water erosion has undermined the foundation, some of it just hanging in the air (especially the far right part). In the not too distant future it will surely collapse. Also, notice on the far left there is a man that tried to climb up the wall (he was unsuccessful).