Spelunking in REM

I have several recurring dreams that revolve around caves. There are three that come to mind.

The first involves a trip to a hole in the ground, from which I descend, with several others, none of whom I know (though at least one person, a man, is always there), into a vast cavern. Once you reach the bottom, there is much to explore, though the details of any exploring escape my memory. Mostly I remember that I get to the hole, go down, wander around a bit, and come back up. This one is quite tame.

The second involves a cave which I have also visited many times, sometimes with others, such as my family, sometimes with strangers, and sometimes alone. I don't remember much about the mouth of the cave, most of what I remember from these dreams is that the cave is huge, and is a lost/abandoned city. I remember taking trips to grocery stores where anything you want can be taken from the shelves. I remember visting the house of a really creepy, mysterious, old lady who still lived in the cave. I remember there being dangerous paths and crossings, and various determinations to find things of importance.

The third repeated itself again last night. In this dream, I remember clearly the hike to the mouth of the cave. Last night, I was the first to get there. When I got there, I realized that I had nothing to drink. In my dream, I remembered that the last time that I had been there (in reality the last time I had dreamed that I had been there), I had had a backpack with a water bottle. Fortunately, there is a convenience store at the top of the mountain where the cave mouth is. I went in, and was considering a gatorade, but they were quickly snatched up by other shoppers. Fortunately, I found a nice water bottle on a shelf and purchased it. In this dream, I remember the mouth of the cave, I remember my drinking needs, and then I am all of the sudden in the cave, on my back, fighting off lunging tigers or leopards or something, which are trying to get at the food that is covering me. I don't know what kind of food, or where it came from, only that I can get them off of me by grabbing their heads, and using my legs to heave them off of a cliff. Last night, I fended off dozens of animals, and remembered that last time I had been in the cave (or the last time that I dreamed it), that I had been pleasantly surprised that I had only had to fight off one tiger/leopard/creature.

Gotta love dreams.

On a completely unrelated cave note, did anyone see this?

http://news.nationalgeographic.com/news/2007/04/photogalleries/giant-crystals-cave/index.html