Beware of darkness

Barnstorm, the University of Wisconsin Press' new volume of short Wisconsin fiction, has a story by Lorrie Moore called "The Jewish Hunter," in which two people visit a touristy cave that's a lightly fictionalized version of the Cave of the Mounds in Blue Mounds, Wis. The story got me to thinking: what are other famous caves in literature? There is, of course, Plato's cave, beloved by cinematic theorists everywhere. There's also Tom and Becky's cave in The Adventures of Tom Sawyer, and there's A Passage to India's famous Marabar cave, in which a colonialist biddy loses her mind.

Others?