It represents the unconscious, so what you find inside can be of utmost importance for you. If it is a crypt, the bodies represent parts of your personality that are no longer active or matters that have been relegated to rest. If the vault is a safe, it symbolizes happiness and opportunities for spiritual unfolding. Treasures contained are your spiritual potential: the reward for having explored the unconscious. Depending on its shape, the vault is also associated with the womb. Its appearance in dreams, in this case, points to the need for feeling protected. You must pay attention to the condition of the vault in the oneiric image because it represents the environment around the dreamer in real life. If it is high and illuminated it indicates well-being; if it is dark and low, confinement; if it is in ruins, material or spiritual poverty. An old book on dreams says that if a man dreams of walking under a vault of black color, he will marry a widow, and will become the slave of her cruelty.