Inside Mammoth Cave, people notice that the air seems surprisingly fresh and that their allergies disappear like magic. Observations such as these have been noted for centuries at least. In 1839, the property was purchased by Dr. John Croghan and entered into a most peculiar situation. While still open for tours, Dr. Croghan devised a plan to use the cave for medical purposes.

Written by Lauren Eisenberg Davis

Sponsored by L.L.Bean