I thought this was a national park but it turns out it is privately owned and operated - it is called a National Natural Landmark: anyways it is every bit as beautiful, professionally managed and unique as federally owned national parks. For the price: $26 : you get a short boat ride from the gift shop/parking area across Lake Shasta (3rd largest body of water in California), a short shuttle bus ride up a winding road with breathtaking views of the lake below, and a guided tour that fills you in first on the history of the lake and Dam starting from the lake overview room and then walks you through the Caverns. Bring a light jacket in summer because the cool breeze blowing inside is chilly for t-shirt and shorts wearers even when outside the Caverns the thermometer is measuring triple digits. Since these Caverns exist in a limestone area on the steep sides of the lake, a large part of the exploration involves climbing stairs from a lower level to progressively higher horizontal chambers. Some of the stairways are a little narrow so be aware if you have claustrophobia. And the 275 steps do make the heart beat a little faster. But the climb is easily worth the effort. I saw cave formations here that I didn't see even in Carlsbad Caverns in New Mexico or in Texas's Natural Bridge Caverns. The large rooms and passageways are very beautiful. The ornate limestone decorations are one of a kind. You end the tour by walking down the mountainside to the cavern entrance reception area (restrooms are available here) on 275 stairs or so on the outside of the caves in an area of dramatic cliffs reminiscent of the Castle Crags rock formation up near Dunsmuir, CA. Handrails keep you safe as you descend and the lake in the valley below with its bridges, curving shoreline, azure sparkle, rolling hills and wandering boats and jet skis is stunning. Then you have a shuttle ride back down from the cave entrance building to the boat landing and a boat ride back to the visitor center and parking lot. Definitely worth the visit.