Discovered in 1918 by two parks' employees who were going fishing, this unique cave was carved by an underground river and has marble formations estimated to be up to 100,000 years old. Tickets for the 50-minute introductory tour are only sold online in advance or at the Giant Forest Museum and Foothills Visitor Center, not at the cave. Bring a jacket.
Stalactites hang like daggers from the cave ceiling, and milky-white marble formations take the shape of ethereal curtains, domes, columns and shields. The cave is also a unique biodiverse habitat for spiders and bats.
Tours fill up quickly, especially on weekends, so buy tickets online at least two days before your trip. Wheelchairs, baby backpacks, purses, strollers, tripods and walking sticks are prohibited inside the cave. Water bottles are available for purchase in the cave bookstore. Note that the cave may close during rainy weather (refunds are available).
From the Lodgepole or foothills areas, allow at least 90 minutes to get to the cave, which is a half-mile walk from the parking lot at the end of a twisty 6.5-mile-long paved road. Look for the signed turnoff for Crystal Cave Rd about 2 miles south of the Giant Forest Museum.