My friends stopped the car and coaxed me to walk with them through the tunnel to one of the ventilation holes. The opening has a security grate to keep someone from getting past but the bars were not so close together that I could not slip the camera out to get this shot.

Water trickling underfoot, the valley floor below and even part of one of the park roads slipping between the trees, this shot shows the sorts of pictures that people might idle think about as their eyes catch the brief glimsp of light from the corners of their eyes.