Huh, I hadn't thought of that. That would go on top of the 6 hex slab that's already there?
EDIT:
Lowered the middle to a 4-hex slab on level 4 and rotated the level 5's out away from the center of the map, and fixed some tile placement errors (floating level 2 water?!?!?), etc.
New link for Silence and Solitude