Significance of The Cave?

Eventually the author and the Aborigines reach a cave in the middle of the desert. Like caves in other archetypal/mythic stories (see "Themes - The Mythic Journey"), this cave represents the instinctive spiritual truths at the core of a journey, and in this case the truths at the core of the author's very existence (see "Characters - The Fortune Teller" and "Tribal Elder").