Ohio Caverns in west-central Ohio near West Liberty is the state’s largest cave system and a long-established public attraction known for its unusually dense crystal formations. The caverns formed from an aquifer that once carried glacial meltwater underground; when the water receded to deeper levels, it left passages where mineral deposits continued to grow. About 90 percent of the stalactites and stalagmites remain active, making the site especially important for observing ongoing cave formation. Its geology is linked to glacial erosion and a surrounding graben in the bedrock, processes associated with the area’s emergence as Ohio’s highest point at 1,549 feet above sea level.