Under a winery on South Bass Island in Lake Erie is the largest geode in the world, a cave you can walk into whose walls are lined with pale-blue celestite (strontium sulphate) crystals up to a foot across. It was found in 1897 while digging a well. PUBLIC tours in season, Put-in-Bay, Ohio, a genuinely one-of-a-kind place to stand inside a crystal.
Celestite (celestine)
See it on the map
Other places on the map within a couple of hours.
