Soul King Palace

is a separate dimension kept suspended above Soul Society that serves as the official residence of the Soul King and its Royal Guard.

Overview
The Soul King Palace consists of several layers, with one layer suspended above the other. 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.

Defenses
The sekkiseki walls that surround Seireitei are ordinarily intended to protect the Soul King Palace, instead meant only to fall down to Seireitei in times of emergency. However, if emergencies occur in succession, they remain in place around Seireitei indefinitely until things are returned to normal.

The Soul King Palace is further protected by 72 barriers between it and the Seireitei. Should these barriers be forced open via clothing constructed from an Ōken, they cannot be closed off for 1 hour and 40 minutes due to the sheer defensive power of the clothing.

There exist a group of elite guards known as which are led by Senjumaru Shutara, who refers to them as the. Each guard wears a black hakama with a purple sash tied around their waist and a black mask with four light-colored lines tracing over their heads, and their hair is tied into a long spike at the back of their head before being left to hang free about halfway through the length. They are all armed with swords.

There is a much more powerful version of these soldiers known as a, which Senjumaru refers to as the. It resembles an ordinary soldier, but is extremely large and wears a circular black hat on its head. The backs of its wrist each have one-half of a large, black, circular shield on them.

Yhwach's Changes
After absorbing the Soul King, Yhwach drastically altered the appearance of the Soul King Palace, most notably by bringing the Wandenreich city to the palace and placing the main palace at ground level while covering parts of it with ice. He also connected the five floating cities nearby to the Wandenreich city, thus creating a massive Quincy Zeichen, and formed a massive, tower-like palace with Silbern on the top for his new stronghold; he labeled this new city the because it would be the cornerstone of his new world. One of the five branches forming the city is known as the.

Admittance
The route to the inner dimension in which the palace resides can only be opened with "a 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. There are only two ways to enter the Spirit King Palace:


 * 1) With the permission of the Royal Guard. They don't have to be there physically, they only need to want the person to enter.
 * 2) Make a Royal Key by creating a Royal Guard.

A Royal Guard can also open up a to send someone directly to the Human World, and use the same gate to send said "someone" back, but to do so requires syncing the arrival and departure times.

Transportation
The only known method to get from section to section of the Soul King Palace is to be catapulted into the sky, in the direction of the intended destination.

Guards
The Royal Guard, also known as the "Zero Division", are the protectors of the Soul King Palace and its residents, particularly the Soul 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.

Trivia

 * Yhwach considers the Soul King Palace to be nothing more than a "decaying grave".