To see a city in your dream signifies your social environment and sense of community.

If you dream of a big city, then it suggests that you need to develop closer ties and relationships. You are feeling alienated and alone.

To dream that you are in a deserted city indicates that you feel rejected by those around you.

To dream of a city in ruins denotes that you are neglecting your social relationships and allowing them to deteriorate.

To dream of an underground or underwater city represents your subconscious and how through deeper understanding of yourself, you find commonality and shared experiences with others.

Dreaming of a city in the sky implies that you are being too idealistic. You have overly high hopes for those around you.