Okay- question time. I think it should be a siege map. QUESTION TIME!
Should there be an underwater entrance? If so, I'm going to make it go from some point in the river/lake to a stairwell on the bottom floor of the base.
Should there be two side entrances? If so, they're going to go from one of the corners in the outer base to some point of the second level. And, the corridor leading from one to the other would be extra-long, as to not make it better than the main entrance.