Very nice map Arcana

To give it more height, you can add shadows to the walls and perhaps play a bit with other shadows.
I also agree with Loydb on the shadows, but for all text. Just add a little perspective shadow and it will all float a little above the map.
To create even more height for the circular staircases, you could add a drop-down shadow that becomes larger when the staircase gets higher.

Excellent work