We did the Big Room self-guided audio tour and the King's Palace guided tour. We thoroughly enjoyed both, and would do them both again. The formations are spectacular in both areas. In the King's Palace tour, they turn the lights out, and our tour guide chose my daughter turn the lights off and on which was a thrill for her. The only downside to the King's Palace tour is the large size of the group, which makes the tour move a little slower than we'd like. The self-guided audio tour in the Big Room allows you to slow down for photos when you want, and speed up when you want. Bring a jacket or long sleeved shirt, the temp is in the 50s.