(Like the recent real Polish jokes, there are Mormon jokes told by Mormons. Some of them you wouldn't get unless you were one, but...)
A man dies and is getting his tour of heaven. His guide is pointing out the various features and landmarks when the man asks, "What's that cliff?"
"Oh, you don't wan to look down there. That's hell!"
The man creeps up to the edge and looks over. He sees lush, green valleys, verdant farmland and trees everywhere. "This doesn't look so bad," he says. Puzzled, the guide comes over and looks down.
"Dang!" he snaps, "Those Mormons have been irrigating again!"