Hundreds of years ago, the Sith Emperor ordered the construction of the Dark Temple as a burial place for his dead and defeated enemies, “to aid them in becoming one with the Force.” Little is known of what rituals the Emperor performed there, but the Dark Temple has become a nexus of powerful dark side energy, and a place where ancient weapons and ancient secrets of the Sith lay sealed away in cavernous chambers.
Although the Dark Temple grounds have always been a dangerous place for the weak-willed (the expansion of the Kaas City power grid into tunnels beneath the temple drove a thousand slaves mad), the temple itself remained sealed until recently, when an expedition of power-hungry Sith Lords and their servants breached the gateway.
The Dark Council did not sanction this intrusion, nor did it punish the rogue Sith; no one returned from the expedition to punish. Violent electrical storms surrounded the temple for the first week after it was opened, and since then, additional expeditions have been sent by the council to determine the temple's status. Their reports have not been made public.