The Crystal Caves were located deep within the side of a mountain cliff on the frozen world of Ilum. The Jedi Order, which discovered the caves circa 22,800 BBY, was given sole access to the world's 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.
Located within the side of a sheer cliff, the entrance to the Crystal Caves was located within the Jedi Temple complex erected by the Jedi Order. The interior of the caves were made of natural shiny black stone; a 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. In the black stone grew the crystals the Jedi used in their sacred weapons, the lightsaber. Many pathways wound their way through the caves, creating a labyrinth of darkness and mystery.
Weaving between the pillars of stone, a bridge was erected that led into a large open area and a dais upon which Jedi completed their lightsabers. The bridge led along the cave's great chasms and to its main door, set in the frozen facade of the cliff wall.
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 on the world as they mined 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 Initiates were still taken to the Crystal Caves to find their lightsaber crystals in the ritual known as The Gathering.
In the months following the Great Jedi Purge, two surviving Jedi, Fy-Tor-Ana and Garen Muln sought refuge from the Galactic Empire in the Crystal Caves. Fy-Tor-Ana eventually left for Coruscant, while Muln remained behind. Ferus Olin rescued Muln a few months later.
When the war concluded and the Galactic Republic and Jedi Order were left in ruin by the Galactic Empire, the Crystal Caves and the Temple were made inaccessible, protected by an Imperial garrison and lost to all remaining Jedi.
- Star Wars: The Old Republic
- Jedi Quest: Path to Truth (First appearance)
- Jedi Quest 1
- I Am a Jedi Apprentice (Mentioned only)
- Star Wars: Clone Wars – "Chapter 14"
- Star Wars: Clone Wars – "Chapter 15"
- Star Wars: Clone Wars – "Chapter 16"
- Star Wars: The Clone Wars – "The Gathering"
- The Last of the Jedi: Dark Warning
- The Last of the Jedi: Underworld (Mentioned only)
- The Last of the Jedi: A Tangled Web (Mentioned only)
- Star Wars: Empire at War (Mentioned only)
- Star Wars: Empire at War: Forces of Corruption (Mentioned only)
- The New Essential Chronology
- "Order 66: Destroy All Jedi"—Star Wars Insider 87
- Star Wars: Empire at War: Forces of Corruption: Prima Official Game Guide
- Jedi vs. Sith: The Essential Guide to the Force
- The Complete Star Wars Encyclopedia
- The Essential Atlas
- The Jedi Path: A Manual for Students of the Force
- Star Wars: The Clone Wars Comic UK 6.47