Central Cortex. I did a rough sketch of it in colored pencil and watercolor a long time ago:
Eh, maybe the picture is to phallic I don't remember how long ago I made it, maybe I was seventeen or eighteen at the time so cut me a little slack. Central Cortex is John Azmodius' home. It's a total fantasy.
There are thirteenth towers, and a massive labyrinth which goes on and on and has cities built inside of it. There is a massive library inside Central Cortex which has two copies of every book that has ever been written inside of it. Which, as you can only imagine, is a lot of friggin' books. Azmodius morphs the rooms to fit his needs or purposes, or the needs and purposes of his guests.
The ominous appearance is just to keep people away, the interior is rather comfortable, mostly decorated like some Victorian fantasy with scroll lined furinshings and damask wallpapers and all of that. I don't need thirteen towers to hide away and read a book, but I wouldn't complain if I had them.