Hōzukijō

Hōzuki-jō (鬼灯城; Literally meaning "Demon Lantern Castle"), also known as the Blood Prison (ブラッド・プリズン, Buraddo Purizun), is a large castle that serves as a criminal containment facility located inKusagakure Kusagakure.

Layout
The castle is situated near a cliff, where beneath is a raging ocean with tremendous currents that will wash up any attempt escapees and drown them. This, along with the imprisonment technique threatening to reduce anyone who reaches a certain distance from Mui to ashes, makes escape virtually impossible. The prison has no regard of the prisoners' circumstances of being sent there, and outside of the convicts' death, allows them to leave only if the village of the prisoner in question sends an official request for release. Apparently, the prison only admits male prisoners.

Security
Aside from the imprisonment technique and the lethal whirlpools surrounding the fortress, the castle itself has certain death traps set up in case prisoners attempt to escape. Also, prisoners usually tried to prevent trouble, resulting in an usually quiet and calm environment. Most likely due to these factors, the security is lax, if not outright incompetent, as even though the guards performed strip and body cavity searches.

Prisoners are let out from morning to sunset for daily exercise and meals, and at the end of the day they are instructed to return to their cells for sleep. Regulation 23 states that attempt escapes or troublemakers result in three days in solitary confinement in the disciplinary cell; clause 6 states second time offenders get five days, third time is a week, and a fourth is permanent.

Trivia

 * The castle is surrounded by the hōzuki plant, also known as Japanese lantern. In Japan, its seeds are used as part of the Bon Festival as offerings to guide the souls of the deceased.
 * The sculpture behind the security desk is the Ecstasy of Saint Theresa by Bernini, which illustrates a moment where divinity intrudes on an earthly body.