Discovered by two boys on a church outing in the 1880s, this impressive underground cavern has offered public tours for well over a century. It provides a good opportunity to see the beauty of the underworld. The 45-minute Discovery Tour takes visitors along a well-lit 3/4-mile passageway through 20 subterranean chambers, complete with classic stalagmites, stalactites, crystal flowers, and limestone canopies. In the Adventure Room, modern lighting techniques return visitors to an era when spelunking was done by candle and lantern. The 1 1/2-hour Lantern Tour follows unpaved and unlighted passageways and corridors. This tour is rather strenuous, with some stooping required in areas with low ceilings; it might muddy your shoes, but not your clothes. Outside and aboveground is the Wind Walker Challenge Course where harnessed participants navigate a maze 600 feet above the canyon below, and a Bat-a-Pult thrill ride ($20 for both); new for 2014 was the Terror-dactyl thrill ride.