Soul King Palace

is the residence of the Spirit King, located in a separate dimension in the very core of Soul Society.

Overview
The Reiōkyū consists of several layers suspended above one another. The lowest level is comprised from many buildings of the same style to that of Seireitei. From this, a large stairway leads upwards to a wide and flat expanse, with both areas at the base and top of these stairs being lined by rows of huge, circular pillars. Floating above are five discs with numerous buildings on each, while suspended higher still is a large cylindrical structure that has a conical top and bottom.

The sekkiseki walls that surround Seireitei are ordinarily intended to protect the Reiōkyū, instead meant only to fall down to Seireitei in times of emergency. However, if such crises occur in succession, they remain in place around Seireitei indefinitely until things are returned to normality.

The route to the inner dimension in which the palace resides can only be opened with a golden, tri-pronged key fittingly named the, the location of which is kept secret, only being passed down verbally from one Gotei 13 Captain-Commander to the next.

Royal Guard
The Royal Guard, also known as the "Zero Division", are the protectors of the Reiōkyū and its residents, particularly the Spirit King. Though they commonly remain within the palace, when the Royal Guard do need to travel, their preferred method of transportation takes the form of a huge pillar called the. While this pillar is able to freely exit the inner dimension, it is unable to return to the palace on its own and is instead entirely reliant on outside assistance to do so, such as Kūkaku Shiba's.