Seireitei

is in the center of Soul Society.

Overview
Seireitei is a circular shiro with four main entrances, ten days walk apart,, each guarded by a Gate Guardian. These gates are called the (in the North), the  (in the East), the  (in the South) and the  (in the West). The gates are so heavy that it takes the full might of Jidanbō Ikkanzaka to lift one, while during the Bount-led attack on Seireitei, siege machines were needed to open the gates. There are, however, doors within the gates, as seen when Momo Hinamori first entered the Shin'ō Academy.

The walls of Seireitei are made of, a rare type of stone known to negate all Reiryoku, similar to magnetic lodestones. The stone also forms a spherical barrier around the city, extending above and below, stopping anything spiritual from breaching it from ground level, from the sky or from underground.

Information about the Seireitei is confidential. What is known is that in the center of the Seireitei is a white tower known as the Senzaikyū, where criminals are imprisoned (similar to death row); on the hill adjacent to it is the Sōkyoku, where prisoners are executed. Those permitted to live in the tranquility of the Seireitei are Shinigami and the few families of the nobility. Shinigami live in the Division barracks, while high-ranking officers commute from their own homes.

The majority of the residents of Seireitei, nobility and Shinigami alike, do not interact with the citizens of Rukongai. However, residents of Rukongai, like Renji and Rukia, are allowed to apply for the Shin'ō Academy, which is often the only escape from the poorest conditions of Rukongai.

Gate Guardians
The Gate Guardians are the guardians of the four gates of Seireitei. They are all giants who have the strength to lift the gates made of Sekkiseki.