Sibyl

To the ancient Greeks and Romans, a sibyl was a woman who lived in a cave and uttered prophecies. Ten Sibyls were known by the places where they lived. For example, the Sibyl of Cumae lived in a cavern near Naples. My brother and his wife gave me a drawing of this cavern from when they lived near there.

English word: We still use the word sibyl to refer to a prophetess, and the adjective sibylline means "oracular."