Obscurity and misfortune are interpreted from these symbols (Gypsy); the ancient and sacred symbolism of caves, grottoes, etc., was lost upon the Jews who regarded them with horror, while popular tradition peopled them with dragons and other evil creatures.... The Fabric of Dream
If you observed the cavern entrance from outside, you can expect that your circumstances will gradually improve; however, if you were in it (or fell into it) and couldn’t get out, you may be up against some hostile influences which could frustrate your ambitions.
The seriousness of your opposition would be indicated by the depth of the cave*L If it seemed very deep, you should reconsider your goal.... The Complete Guide to Interpreting Your Dreams
Usually we live on the surface of our mind. In sleep we dive down deeper but lose our sense of self.
If we maintain some awareness in these deeps of the mind, it is somewhat like snorkelling in deep sea; we realise what immense and unbelievable depths lie beneath us. Dreams often portray this as depth—a hole, deep water, a chasm; space; our non-verbal life in the womb, or early childhood, which is remembered as patterns of feeling reaction rather than verbal utterance. In the depths we may find gems, skeletons, archaeological objects, and these relate to the memory of our evolutionary past, family influences we carry within us unknown. Deep cuts: suggests a hurt which penetrates us; or emotions which affect us powerfully. Idioms: in deep water, in the deep end; deeply troubled; deeply hurt. ... A Guide to Dreams and Sleep Experiences
Psychological / emotional perspective: We may be trying to understand archetypal patterns that have not been recognizable in the past. There is information available to us which we can only understand through being able to appreciate our own emotional depths.... Dream Meanings of Versatile
Material aspects: When we dream of the deep we are usually considering past family influences of which we may not be consciously aware. Patterns of behaviour are often repeated in families and it takes some dredging through family stories and myths to have us recognize such patterns.... Dream Meanings of Versatile
Any sense of depth, particularly going down, in a dream usually represents the unconscious mind.
This can be accompanied by feelings of discovery or dread. “Deep” is also found in a number of interesting idioms, such as at the “deep end” or in “deep water.” One can be deeply hurt or deeply troubled.... Dream Symbols in The Dream Encyclopedia
Unlike rivers and seas, lakes, lagoons, pools, ponds and puddles are typically still, so if they feature in your dream, they could be reflecting your emotional calm.
If a lagoon appears mysteriously, reminding you that still waters run deep, this could be referring to your own hidden strengths or weaknesses. Some dream researchers believe that lagoons in dreams are symbols of the womb, so perhaps when they appear in a dream, you are longing to retreat to a safe haven.
If you are a woman, they may refer to a desire for children and if you are a man, a longing for intimacy. Dream ponds can also reflect your unconscious personality, facets of which will be represented by the creatures who live in it.
If your dream pond is lifeless and stagnant, is your emotional life currently unfulfilling? If you watched a fish swim to the surface, could it have represented the emergence of your intuition? If the pool suddenly transforms into a whirlpool or maelstrom, this suggests emotional turbulence or confusion in waking life.... The Element Encyclopedia