Illinois Caverns April, 2006 We went caving in Illinois Caverns in April. We camped at Camp Vandeventer near Waterloo and drove to the cave on Saturday. It is a wild cave that is owned by the state and made open to the public. It's at the bottom of a large sink hole that has concrete stairs leading down into it. There are no sidewalks or electric lights in the cave, but there is plenty of water and mud. After their turn in the cave, the younger Scouts took a long hike around the camp on what had turned into a great spring day.