The correct ordering of the words in Spanish should be Mundo Hueco
1 is a fictional dimension in the manga and anime series Bleach, where the series' main antagonists, the hollows, reside.
2 is located between the living world and Soul Society. It can only be accessed by ripping a hole in the dimensional fabric separating the worlds, or using a special technique known as a garganta (Spanish for throat). The hollows can travel to and from Hueco Mundo at will. The landscape of Hueco Mundo is a seemingly neverending white desert, with dunes like those of the Sahara. The desert is littered with what appear to be boulders and dead, 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. Like Soul Society, the atmosphere is filled with spiritual energy, but it is much more concentrated in Hueco Mundo than it is in Soul Society,2 thus allowing hollows to gain nourishment despite the lack of human souls.