Location from Bleach by Tite Kubo
The floating palace high above Soul Society where the Soul King is sealed in crystal and the Royal Guard — five Shinigami stronger than the entire Gotei 13 — stand watch.
The Soul King Palace exists in deliberate isolation. Reaching it requires the Ōken or a Royal Guard escort — there is no casual access. The five members of Squad Zero each earned their position by creating something foundational to Soul Society: Nimaiya forged the original Zanpakutō, Hikifune invented the Gikon, Kirinji created the healing hot springs. Their combined strength exceeds all thirteen Gotei captains. At the palace's heart, the Soul King — a limbless, eyeless being sealed in crystal — serves as the linchpin holding all three dimensions together. Yhwach's invasion of the palace and assassination of the Soul King nearly collapsed reality itself.
A cluster of floating islands connected by bridges, suspended far above Seireitei in a separate dimensional space. Each of the five Royal Guard members maintains their own city-sized platform. Architecture ranges from palatial to bizarre — one island is a giant hot spring, another an enormous kitchen. The Soul King's chamber sits at the center: a silent crystalline room.
Also known as: Soul King Palace, Reiōkyū, Royal Palace