The cave was discovered by Jack McGann, a local herdsman, in 1940. One day, Jacko was looking after his sheep at the foot of Aillwee Mountain with his dog. The dog gave chase to a rabbit, following it up the mountain and into a small opening in the rocks. Jacko explored this opening with nothing but a candle to guide his way, finding his way right as far as the Great Cascade
Guided tours take you through the 1000 feet long cave where you can see underground waterfalls, unique mineral formatins and hibernation chambers of now extinct brown bears.