Hueco Mundo

is the dimension where Hollows and Arrancar usually reside. It lies in between the world of the living and the Soul Society.

Overview
A large portion of Hueco Mundo is covered by a desert, a silent world of death. An unchanging night covers the sky, an endless white desert covers the ground. The tree-like objects are not plants, but rather quartz-like minerals.

The landscape of Hueco Mundo is a seemingly never-ending white desert, with a multitude of dunes. The desert is littered with what appear to be boulders and shriveled trees, but these are actually a form of quartz. In Hueco Mundo, the moon is on the opposite lunar phase of that in the Human World. The vast desert also seems to lack any bodies of water and contains rocky formations. Like in Soul Society, the atmosphere is filled with a high concentration of Reishi, thus allowing smaller Hollows to gain nourishment despite the lack of Human souls.

Like that in real world deserts, active life in Hueco Mundo appears to be few and far between. Hollows generally seem to dwell below the surface or in other areas until something provokes them to leave their shelter, like the intrusion of a foreign entity. According to the Shinigami, all Hollows dwell in Hueco Mundo regardless of their shape, size, or power.

Accessing Hueco Mundo
Hueco Mundo is located between the Human world and Soul Society, though it is separated from the bordering dimension known as Dangai. It can only be accessed via Garganta, which tears the dimensional fabric separating the worlds, allowing Hollows to travel to any other dimension at will.

Government
Hueco Mundo has no formal government. In Hueco Mundo the strongest being wields power, though even if there is no particular leader or organization Hueco Mundo runs as usual.

Espada
Ten of the most powerful Arrancars. Ranked 0 through 9 depending on their combat ability. Their ranks are tattooed on their bodies.

Fracciónes
Arrancars who serve under the Espadas. The Espadas are allowed to have as many Fracciónes as they want.

Privaron Espada
Arrancars stripped of their Espada rank and given a Tres Cifras rank.

Exequias
A unit responsible for eliminating intruders in Las Noches. They recovered battle records from Arrancars that were defeated by Ichigo Kurosaki.

Las Noches
Las Noches is also located in Hueco Mundo. Formerly ruled by Baraggan Louisenbairn, King of Hueco Mundo, it became the headquarters of Sōsuke Aizen and his army of Arrancar for a short time.

Forest of Menos
As explained in an anime-only filler, there exists a vast forest underneath Hueco Mundo where Menos-class Hollows reside. The trees in this forest extend to the surface and dot the landscape above ground. The Adjuchas-class Menos which reside in this forest are under the control of Aizen.

Navigation
Hueco Mundo Hueco Mundo Hueco Mundo