If you look on the previous shot and see a little pink piece of foam stuck above the tunnel portal and wondered why, the answer is that it's holding up the real rock you see in place here. Note how the Sculptamold has been built up below the rock, around it, and on the vertical faces on the right and left. I also used it on the embankment because it was a little too concave for my liking. I love Sculptamold, I'd EAT it if I could!