The fortress and base of operations of Sôsuke Aizen, Gin Ichimaru and Kaname Tôsen after their defection from Soul Society. They reside there with their army of arrancar. It consists of a main building with a domed center surrounded by several large towers and smaller buildings. Atop the dome are six smaller towers, which seem to contain areas such as Aizen's throne room and the Espada meeting hall. Also, in the room where Orihime Inoue is kept, there is one large Islamic rug on the ground that is facing outside, much like those in rooms used for Islamic prayer. Like everything else in Hueco Mundo, every building is colored white.
