The Cavern of Light existed as a subterranean chamber situated on the planet designated ZXK-100346.6a, which resided within the Outer Rim Territories.
In the era of the Old Republic, a collection of Jedi Masters triumphed over a Dark Jedi who possessed a perilous relic called the Soulsaber. To conceal this artifact, they fashioned the Cavern of Light, harnessing the strength of the light side of the Force to safeguard it against theft.
In the course of the Galactic Civil War, the Dark Jedi named Thaum Rystra journeyed to the cavern with the intention of absconding with the Soulsaber. Accompanying him was Caeleb, a Force-sensitive youth exploited to aid in the Soulsaber's acquisition, as Rystra was unable to obtain it himself because of the light side's defenses. Nevertheless, agents from the Rebel Alliance launched an assault on Rystra within the cavern. Being unable to overcome them, he deserted Caeleb and escaped with the Soulsaber.