A fortress can be seen as a refuge, protection and assurance of safety. The fortress in a dream signifies the security that we have in our dreams. We’re safe from any harm because we’re living in our own world where nothing bad has happened to us.
The fortress in a dream also represents the different aspects of life that we can choose from to live safely and happily.
For example, if a dreamer is being chased by someone and they find refuge in a fortress then this could signify protection from evil forces. But if the dreamer finds themselves lost or locked out, it may represent feeling of isolation.