See celestine crystals up to 3 feet in width! Discovered by workers in 1897 while digging a well for the winery 40 feet above, Crystal Cave is the world's largest geode. The walls of this cave are covered in strontium sulfate, a blueish mineral called celestite. These crystals range from 8 to 18 inches long.

Owned and operated by Heineman Winery, Crystal Cave helped save the family-run winery from demise during Prohibition. The Heineman Winery was founded in 1888 by Gustav Heineman, an immigrant from Baden, Germany, the grape-growing region of that country. The Lake Erie Islands were already noted for quality grapes as a result of ideal soil conditions and the long growing season because of the tempering effect of Lake Erie.