The Iron Citadel, a legendary palace of immense stone construction, was said to have been located on the planet Empress Teta within the Deep Core. The Qel-Droma Epics, considered a collection of semi-historical tales, claim it once safeguarded the crown jewels of Koros Major, before its eventual capture by the Krath. Later, it functioned as the base of operations for the disgraced Jedi, Ulic Qel-Droma. By the Imperial Era, its very existence was questioned by many outside the Empress Teta system.
As recounted in the Qel-Droma Epics, the Iron Citadel's name derived from its iron fortifications, believed to be impenetrable. The citadel had successfully resisted invasions and infiltrations from various factions, including the Galactic Republic, Mandalorians, Sith, and the Jedi Order, before it was ultimately seized by the Krath following a military coup. Subsequently, it became a crucial command hub during their violent crusade against the Jedi Order. The epics also detail how Mandalorian Crusaders under Qel-Droma launched attacks from the fortress, riding Basilisk war droids into battle.
Despite its status as a fabled location, scholars of the Qel-Droma Epics during the Imperial era launched unsuccessful expeditions in search of the ancient battlefields and relics from a bygone era of heroes. Among the artifacts rumored to be housed within the ruins were Ulic-Qel Droma's lightsaber crystal, Satal Keto's Krath Translation Talisman, and a functioning Basilisk war droid. The existence of the citadel was widely doubted outside of the Empress Teta system. Local inhabitants of the planet asserted that it formed the foundation of the present-day Tetan Royal Palace, while a small number theorized that it lay buried beneath the modern cityscape, serving as a sanctuary for surviving Krath loyalists. Still others speculated that the Republic had destroyed the citadel when they reclaimed the system from the Krath.