- "You—go to the isolation chambers in the pits beneath the temples. If my plan fails, you will be a last surprise for them!"
- ―Exar Kun to Kalgrath
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.
Shortly after the Battle of Yavin, a TIE/sa bomber starfighter of the Galactic Empire crashed on the Great Temple, which caused damage in the isolation rooms and woke up Kalgrath. The hero of the Rebel Alliance Luke Skywalker used the Force to open the blank wall and discovered the isolation rooms, where he learned about the ancient Massassi and their last guardian.