Underground 
To dream that you are living underground signifies a loss of status, wealth, and the longing for a greater piece of mind and sanctuary. You may be placing these matters and thoughts into the subliminal part of your mind.
To dream while you are riding in an underground railroad represents anguish and concern rising up from an unusual activity.
Silo
To dream of a silo implies that you should be more frugal with your finances. It's possible that you are purchasing items that you don't need or are too expensive. You should instead try to save and accumulate a nest egg.
Sewer
To dream of a sewer represents a state of decay in former friendships or associations. It indicates the necessity for purification or urgent alterations.
Subway
To dream that you are in the subway implies that you are attaining your objectives without having to use much physical effort. You are discovering your inner spirituality and personality. It may also mean that you are being too impulsive and you should think carefully before making a decision.
Tunnel
To dream of a tunnel represents the main female reproductive organ, the womb, and giving birth. Hence, it may indicate your need for protection and nurturing.
To dream that you are going through a tunnel suggests that you are discovering parts of your unconscious. You are in the process of gaining understanding and enlightenment. Alternatively, it may indicate your myopic nature.
To see light at the end of the tunnel symbolizes hope and a brighter future.
Cellar
To dream that you are in a cellar symbolizes the area in your mind where you tend to bury your concerns and painful issues.
To dream that you are going down a cellar implies that you are prepared to confront these issues that you have been avoiding. You are ready to put the past behind you and move on with your life.
Dungeon
To dream about being in a dungeon indicates that you will rise above roadblocks in life through your intelligence and perseverance.
Anthill
The presence of an anthill in your dream symbolizes cooperation and productivity. Try to relinquish control. It can be tempting to take everything on yourself, but be careful not to underestimate the power of teamwork.
Bomb Shelter
Being inside a bomb shelter in your dream means you need to protect yourself from unexpected ridicule, sadness or anger. Someone's anger or frustration may be affecting you negatively which could end up hurting you emotionally or physically. Your dream is alerting you by placing yourself inside a bomb shelter to shield you from this or some other type of pain, rage, mockery or misery caused by someone.
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