Sonny is listening to the speaker phone they give you (for a price) and you punch in the number you see at the different stops and it tells you what you are looking at. One of the Rangers that was keeping an eye on my hands. lol I ask him how long it took for the drips of water that come from above to build something like what you see and he said thousands of years. Most of the cavern that we are in isn't active anymore because of Man. Good intentions but a paved parking lot and a great big building stopped most of the seepage into the cave. Although we did get dripped on at times so some of it is still alive.