Ryōzanpaku

Ryōzanpaku (梁山泊 (梁山城夜景), literally "Dragons Opening the Night"; also translated as "where the strong and ambitious gather") is the official residence of the Kata Society, located in a separate dimension in the far outreaches of Soul Society.

Admittance
It is only possible to enter Ryōzanpaku through the Fūsayaburi (封鎖破り, "Dam-Breaking"; referring to a dam tearing down and letting the river continue flowing undisturbed) technique.

Behind the Scenes
In the Chinese tale of the Water Margin, Ryōzanpaku is the place where the 108 Stars of Destiny regarded as their stronghold as well as the location where they would train together at Liangshan (梁山). The mountain that the city resides in this fictional work is suggested to be a parallel to Mount Liang.