From a mundane perspective if we are to live life as fully as we can, we need to understand our own tower.
In dreams it may appear initially as far away and later coming closer. How we get into the tower is also important.
Shallow steps indicate that we have easy access to our inner self. More difficult steps suggest that we are fairly private individuals.
If the door is barred or particularly difficult to open we are not yet ready to explore our unconscious self.
If the door is closed we must make an effort to get in.
If inside the tower is dark, we are still afraid of our subconscious.
The hidden room in the tower would have the same significance as in a house.