the mountain and the crater are similar. There was nothing of conscious structure in these fantasies, they were just events that happened. So I assume that Dante got his ideas from the same archetypes
Jung, glossing his own Red Book fantasies in the 1925 seminar, identifies crater and mountain as structurally equivalent — both are archetypal forms expressing the Gnostic principle of reversed symmetry between above and below.
, The Red Book: Liber Novus, 2009thesis