CompuServe Messages

While checking out a small limestone gorge nearby, I found an opening in the side of the wall about 5' high and 2' wide. On a whim, I walked to the other side of the gorge and found a similar opening. I'm no geologist, but what I think I found is an old underground stream that ran perpendicular to the existing gorge. They caves/holes seem big enough to crawl into, but I was wondering what I was getting into. Does anyone have experience with caving? What should I watch out for? How far in can I go without worrying about air? I'm scared of creepy-crawly things, so how can I make sure bats or whatever haven't set up a home. Joe Hayes