The Tower's structure...

Hey fellow regulars, Asriel-SIU here to ask you a rather pointless question about a detail from ToG's lore. It might have been asked many times before, but does someone know how the Tower is structured?

I mean, I know there's the Inner Area that we see throughout the adventures with regulars, floors and stuff, the Outer Area where the inhabitant of the Tower that lived here even before Jahad came in and became their King and the kind of weird paths that Yuri used to go to the true 1st floor.

Does someone know how all of this fit? (without using the drawing of the 15 first chapters that I obviously didn't get)...