It provides the basis for certain identifications, such as the medieval one: the cave referred to the human heart as the spiritual "center." The cave, in this case, represents the unconscious, your subjective world, the experiences and knowledge accumulated over the years. All this allows you to reach maturity. It is very common dream during adolescence. The events happening inside the cave will reveal which aspects of the Self you are working on. In other interpretations, the cave represents the womb or female sexuality. What you find in it will be those elements the unconscious wants to cultivate in your: virtues, ideas, attitudes, etc. Many dragons and monsters from mythology lived in caves guarding a great treasure. This symbolizes that before winning the spiritual reward, you must fight the unconscious' fears. The cavern may also represent memories about a traumatic childhood that have been banished from conscious memory.