The cave is really more of a cavern in the side of the bluff looking out on the Ohio River. The cave was used by pirates and scoundrels to rob people going up and down the river in the past. If you stay in the lodge, they have a 1-hour History Channel documentary on the cave in each room. The cave itself is not all that impressive, but you should see it if you are in the town of Cave-in-Rock. It is the town's namesake. It is free to go into the cave and there isn't much exploring to do.
My nieces loved climbing around on the sides of the cave, which have been eroded away by flood water. From the top of the bluff, you can look down through a grate into the cave. Inside the cave, if you look up, you will see names burned into the ceiling. These were done when flood waters were high in the cave. The cave had no water running in it while we were there because the river was at a normal height. My favorite part of the cave was the pictures I got from inside. Check them out!!