Las Noches

Las Noches
Las Noches (虚夜宮, Spanish for The Nights) is the fortress located in Hueco Mundo and base of operations of Sōsuke Aizen, Gin Ichimaru and Kaname Tōsen after their defection from Soul Society. They reside there with their army of Arrancar.

Las Noches consists of a main building with a domed center surrounded by several large towers and smaller buildings. Atop the dome are six smaller towers (or as they appear), 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 Middle-Eastern 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.

Las Noches is easily the largest building structure in the Bleach universe, appearing as large as (if not larger than) Seireitei in Soul Society. Due to its immense size, Ichigo Kurosaki once commented that it could be an illusion as he, Chad, and Uryū Ishida did not seem to make any progress getting closer to it, despite running until they were exhausted. Also, according to the arrancar Nel Tu, it takes about three days to move around its width. Aaroniero Arruruerie claimed that the inside of the dome of Las Noches is sky blue, created by Aizen, so that the light of the sky would help him observe anywhere that he wishes. However, given that he was masquerading as Kaien Shiba at the time, this may only have been an excuse for him to stay out of the sun, and as such may not be accurate. The position of the halls within the palace can also be adjusted, allowing the one operating them to direct the movements of intruders.