Dr. M. Graham Clark knew about the cave under his property. He told me about how National Geographic had taken pictures of it and told him it was one of the prettiest caves they had seen. He hadn't been in it himself since the only way in was to rappel into it. Since Dr. Clark was friends with Johnny Morris, I can't imagine he didn't share the same story with him. I am just not buying that he was surprised to find it. No doubt he was surprised for it to open up, but its existence was no surprise to people who spent time with Dr. Clark.