The two major features of the caverns accessible to the public are the Throne Room and the Big Room. The Throne Room contains one of the world's longest () soda straw stalactites and a high column called Kubla Khan, after the poem. The Big Room contains the world's most extensive formation of brushite moonmilk. Big Room cave tours are closed during the summer for several months (April 15 to October 15) each year because it is a nursery roost for cave bats, however the Throne Room tours remain open year-round.