Alabaster Caverns lies about 30 miles south of Alva near the town of Freedom. The main cavern is a 200-million-year-old gypsum cave roughly three-quarters of a mile long; guided tours run hourly and last about 45 minutes. The temperature inside stays at 50°F regardless of the weather outside, so bring a sweater.
The surrounding state park has hiking trails, a campground, and several smaller wild caves that require a permit and your own light. The cave bats and the bowl of cedar-dotted canyon around the entrance make this one of the most distinctive landscapes in northwestern Oklahoma.