In A Passage to India the Marabar caves symbolize the forces of nature and the power they exert upon the soul. There is something at once terrifying and sublime about these ancient rock formations, something that forces visitors—especially English visitors such as Adela and Mrs. Moore—to confront a previously unexplored spiritual side, one which they had largely neglected.
Exploring the caves is a metaphor for the exploration of one's soul, one's whole spiritual being. And in exploring both, Adela and Mrs. Moore come to see themselves as part of a fundamental unity, in which everyone and everything is linked together. Here, the differences of the phenomenal world—between men and women, Indian and British—no longer apply. All meaning as previously understood dissolves, forcing Adela and Mrs. Moore to wake up to the unreality of their daily lives in the world outside the caves.