Locales
Human world
The human world of Bleach is modern Japan, or specifically, a Tokyo neighbourhood known as Karakura Town.[1] In this world, Ichigo attends school, fights hollows, and tries to avoid rumors that he is Rukia's boyfriend. Places of note are the high school, the Urahara Shop, the river where Ichigo's mother was killed, the cemetery, and Ichigo and Orihime's homes.
Soul Society
Soul Society corresponds to the afterlife, or heaven, in human belief systems. It consists of a giant walled city in the center, known as the Seireitei (Court of Pure Souls), and four regions (north, south, east, and west), each with 80 districts, outside of it. The districts outside of the Seireitei are known as the Rukongai (Town of Wandering Spirits) and are the place where non-shinigami and non-nobles live. The district number of the Rukongai also describes its conditions. District 1 is peaceful and orderly, while District 80 is filled with criminals and has poor conditions. A king resides in Soul Society, but no details about him have surfaced.
Hueco Mundo
Hueco Mundo is the area between the human world and Soul Society. Literally meaning "hollow world" (in Spanish), it is where hollows reside when not in the human world or Soul Society, and where they are nigh undetectable. The entrance to Hueco Mundo is a rip in the fabric of the human world.
Hell
Hell is the destination of those who committed unforgivably evil acts during their lives in the human world. Judging by the incident with Shrieker, when a hollow whose mortal soul is too wicked to enter Soul Society has its mask split by a zanpakutō, the gates of Hell (giant doors with a skeleton holding on to each) appear and begin to open, and a giant, laughing spiritual being with a blade will spear the wicked spirit and drag it down into Hell.
Crossing between worlds
It is known that shinigami and hollows alike can come and go between Soul Society and the human world as they please. Shinigami can cross from the Soul Society to the human world by way of a passage that may be unlocked by their zanpakutō. However, to safely cross over, they must be accompanied by a hell butterfly (a black moth created from soul burial that can perform a multitude of tasks). Hollows can cross over to both Soul Society and the human world by opening a rift in space, although they don't usually dare to enter Soul Society. Humans can also enter Soul Society, if they are able to enter a portal from the living world.