Side A: In 1897, a farm boy investigating the disappearance of water into a sinkhole in a nearby field discovered this system of subterranean passageways. Digging down a few feet, he found an opening to a cave that had begun forming perhaps several thousand years earlier during the Ice Age in soluble limestone bedrock that was approximately 400 million years old. Ground water dripping down from the cavern’s ceiling continues to form stalactites, stalagmites, and mineral coatings on the cavern’s walls, floor, and ceiling. A portion of Ohio Caverns near the discovery site was opened to the public in 1897, but that section closed in 1925 when a more extensive and geologically interesting part of the cave was discovered. Ohio Caverns is the largest known cave system in the state and is widely considered to be the most beautiful of all Ohio caves.