Crystal Cave

Crystal Cave is a cave in Richmond Township, near Kutztown, in Berks County, Pennsylvania, United States, the heart of Pennsylvania Dutch Country. It was discovered by William Merkel and John Gehret on November 12, 1871, and quickly became a popular tourist attraction. Shortly after its discovery, newspapers reported that it was "more beautiful than the famous Mammoth cave in Kentucky." The first "show cave" to open in Pennsylvania, it remains one of the oldest continuously operating show caves in the United States.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).