Crystal Caves The Crystal Caves of Ilum were a legendary pilgrimage site for the Jedi Order from the time of their discovery circa 22 , 800 BBY until the destruction of the Order in 19 BBY . Located deep within the side of Ilum ' s largest mountain range , the caves stretched untold kilometers into the planet and contained a wealth of precious crystals which were vital to the construction of the Order ' s lightsabers . Erecting a Temple at the mouth of the cave , Ilum ' s caves became a traditional journey point for many Jedi over the centuries . Description . Located within Ilum ' s largest mountain range , the Crystal Caves were a potentially tens of thousands of kilometers - deep labyrinth of winging tunnels , bottomless shafts , and narrow corridors that wended their way through the heart of the mountains and deep below the surface of the planet . Despite their importance to the Jedi Order during the millennia over which they were mined , the caves ' total area remained unknown . The Jedi kept charts of the paths near the entrance , but beyond that was a series of dead - ends , crevasses , or a maze of confusing , winding passageways . The largest natural entrance to the caves is the site of the Order ' s primary Jedi Temple facility on the world . The interior of the caves were made of natural shiny black stone ; a volcanic rock that swallowed light instead of reflecting it . As time progressed and the Jedi Order grew , the many Jedi that visited the cave recorded their histories on its walls . A variety of Adegan crystal s grew unimpeded in the walls , floors , and ceilings of the tunnels , and could easily be removed by hand or with hand - held excavation equipment . In some areas the crystals were so common they littered the floor . The caves themselves were a powerful nexus of Force energy , creating a vergence within the Force itself . Due to the potency of the Force within the close confines of the caves , the place had a disorienting effect that was high distressing to most who entered into the depths . Many who entered suffered from vivid hallucinations , and the occasional Jedi has been lost forever in the darkness . Another effect that the caves often created in the minds of the young Jedi searching for their first lightsaber crystal masked the presence of the crystals . Padawans would journey through the tunnels following the Force to the crystal that called to them , and only that one was visible to their eyes . History . Discovered by scouts for the Jedi Order circa 22 , 800 BBY , the frozen world of Ilum was discovered to hold a number of hidden treasure troves where crystals grew naturally . These crystals , prized for their usage as a focus lens in the Order ' s symbolic weapon , the lightsaber , encouraged the Jedi to found a Temple and training ground at the mouth to these caves so that members of the Order could mine the rare kathracite , mephite , and pontite crystals . During the Great Galactic War between the resurgent Sith Empire and the Republic the caves were taken by the Empire in a swift battle . As the Empire began to garrison troops on the world , the Temple was made inaccessible and , due to thinly - stretched resources , the Order was unable to reclaim it for over a decade . Following the destruction of the Sith Empire the Order restored their Temple on Ilum and once more maintained a small group of Jedi on the planet to protect their coveted crystals . The Caves were once more made inaccessible several millennia later during the Clone Wars , a deadly conflict between the Republic and the Confederacy of Independent Systems . During a skirmish between Confederate probe droids and Jedi , several bombs were placed throughout the Temple and damaged the entrance to the caves . Following the attack , the Jedi High Council determined that the coordinates to the secret Jedi world were compromised , the Council ordered that all crystals be harvested and taken to the Coruscant Jedi Temple for safe keeping . Yet Jedi Initiate s were still taken to the Crystal Caves to find their lightsaber crystal s in the ritual known as The Gathering . As Order 66 was executed by the Grand Army of the Republic and the Order systematically wiped out , Ilum ' s prized crystal caves were seized by the Galactic Empire . Blocking access to the Temple at the mouth of the caves , the subterranean depths were largely inaccessible . In the months following the Great Jedi Purge , two surviving Jedi , Fy - Tor - Ana and Garen Muln sought refuge from the in the Crystal Caves . Fy - Tor - Ana eventually left for Coruscant , while Muln remained behind . Ferus Olin rescued Muln a few months later .