Jewel Cave National Monument

Category: Caves

Named for the jewel-like Nailhead & Dogtooth Spar crystals which line over 100 miles of passages, Jewel Cave is the second-longest cave in the U.S. Elevators take visitors 234 feet beneath the surface. Scenic tours from May-Sept. Historic tours June-Aug. Spelunking themed tours mid-June-mid -Aug. Guide fee for tours. Free visitor center open year round. 13 miles west of Custer on US 16