The isolation chambers were hidden rooms housed in the subterranean galleries of the Great Temple on Yavin 4. Their purpose was to host the Massassi warrior Kalgrath, who was put in hibernation in 3996 BBY. The chambers contained a suspended animation capsule and a primitive computer in which part of the history of the Massassi was preserved. A secret underground corridor to the rooms was located behind a blank wall in the Temple main hall, which had become the Massassi Station's hangar by the time of the Galactic Civil War.