Crystal Cave

51 Most Romantic Places in the U.S.A.

"Those planning on popping the question can do so here with the aid of a larger-than-life stone. Crystal Cave is not a cave in the traditional sense, but rather the interior of the world's largest geode, discovered in 1897 by workers who were building a well. Today, you can tour the inside of the geode — whose walls are lined with crystals as big as 18 inches in length — on a visit to Heineman's Winery. The winery, located on the Lake Erie island town of Put-in-Bay, has offered tours of the cave on their property for more than 100 years." - Travel + Leisure Editors