Royal Penitentiary No. 4 is a prison in Khura'in which is located at the very top of the mountain where the Inner Sanctum lies. Prisoners can only be brought to the penitentiary by helicopter. This requires permission from the Minister of Justice, as he is the only one who can authorize flights that pass over the Inner Sanctum.
Defiant Dragons member Datz Are'bal was briefly imprisoned here, with his ID number being 201, following his capture by the rebel hunter masquerading as Lady Kee'ra. However, with the help of some other rebels, he escaped shortly before the Purification Rite using a parachute sewn out of flags. A guard appeared at his cell that night to take him in for more questioning, and he found some blankets in his bed that made it look like he was sleeping. He proceeded to have the alarm sounded for the prisoner's escape.