Went down the stone staircase of the thrid tower. Beside the small telescope I can see the tram below. Go to the edge of the cliff. Can see the tram better now, but cannot get inside. Curser never shows the hand pointing down. I am not carrying a tablet. What to do?

Did you fiddle with the lever on the platform below the first tower? If so (and I imagine you did, else I don't think you could have gotten where you are now), you may want to fiddle with it in the other direction .