At the bottom of the Devil’s Slide trail, there are the remains of a building. This appears to have been a lookout location. There were a number of military installations here at one point. Just south of the tunnel entrance and up on the headland is the concrete core of what was once one of the buildings. The ground has eroded away at the base of the structure and the walls have gone in some places but the concrete core is still there. It has been covered by graffiti artists over the years and is still popular with the more adventurous types. A couple was climbing into it while we were there. It looks pretty cool on a sunny day. On a cold and foggy day, I suspect it will be a bit more depressing.