Citadel Station, also referred to as the Citadel, was a prison facility established by the Galactic Republic on the planet of Lola Sayu, intended for the containment of wayward Jedi. Early during the Clone Wars conflict, the Confederacy of Independent Systems seized control, with Osi Sobeck appointed as its warden. Within its walls, Jedi Master Even Piell, along with officers such as Captain Wilhuff Tarkin, were held and subjected to interrogation regarding the coordinates for the Nexus hyperspace route. However, a rescue operation conducted by a squad of Jedi and clone troopers successfully liberated them. The rescue team was forced to request a fleet be sent to the planet after their only means of escape was destroyed. Later, during the Imperial era, the Citadel served as a Separatist holdout.
This tower-like structure, the Citadel, was built on the planet Lola Sayu. It was positioned across a bridge spanning two yellow lava lakes and drew its power from geothermal sources. Widely considered an impenetrable prison, the Citadel featured a front section that jutted out over the lava, while its rear opened onto a landing field fortified with fences and security installations. The Citadel's outer walls were fortified with hundreds of electromines, which, coupled with the planet's strong winds, prevented unauthorized entry by pushing intruders into the lava lakes below. Searchlights scanned the perimeter, and every door along the outer wall was shielded by a ray shield.
Inside the Citadel, a complex network of identical hallways and corridors awaited. Each hallway was defended by electrified walls, magnetic ceilings and floors, rapidly closing blast doors, cameras, and automated lasers. The central control room, situated atop the prison tower, monitored all security equipment. Outside, a landing platform was guarded by two manned turrets.
Originally constructed in 522 BBY, the Citadel was conceived by the Galactic Republic as a detention facility for rogue or dark Jedi. In 520 BBY, the Citadel housed a rogue Jedi who was imprisoned within its walls. Between 82 BBY and 68 BBY, rumors circulated among the Jedi that the Jedi Council had established a new correctional unit at the Citadel for Jedi with foresight. Following this, Jedi Master Lene Kostana withheld information from the Jedi Council regarding the worsening Force visions afflicting Jedi Padawan Sifo-Dyas, fearing his confinement at the Citadel. This was after Dooku and Dyas met on a mission to the Outer Rim planet Asusto. Kostana later met with Dooku at a hangar within the Jedi Temple on Coruscant after Dooku had a sparring session with Jedi Rael Averross. During their conversation, she shared the rumor with Dooku, who dismissed it but pledged not to cause Dyas any "distress" regarding the matter. By the time of the Clone Wars, the Jedi Archives contained information on the original layout of the Citadel, though it was considered outdated.
During the Clone Wars, the Confederacy of Independent Systems gained control of the Citadel. Osi Sobeck served as its warden, known for his sadistic tendencies. Under Separatist rule, the Citadel became renowned as the Confederacy's most isolated detention center, housing high-value detainees. The prison was heavily guarded by numerous droids, including BX-series droid commandos, and fortified with hundreds of electromines. The clone trooper training facilities at Tipoca City on Kamino incorporated a training course named after the prison, the Citadel Challenge.
In 20 BBY, Jedi General Even Piell and his officers were captured. Piell was subsequently imprisoned and tortured within the Citadel to extract information about the Nexus Route, prompting the Jedi Council to dispatch an elite rescue team led by Jedi Generals Obi-Wan Kenobi and Anakin Skywalker to secure his release. After evading the Separatist fleet's life-form sensors, the team landed near the Citadel using a stolen Sheathipede-class transport shuttle. As they scaled a cliff dotted with electromines, clone trooper "Charger" triggered a mine, resulting in his dying and alerting the Separatists. Nevertheless, the task force infiltrated the prison and rescued Piell, Captain Wilhuff Tarkin, as well as several Clone naval officers and troopers.
During their rendezvous with the evacuation team, consisting of astromech droid R2-D2 and reprogrammed Separatist battle droids, a firefight erupted on the landing pad. Republic ARC trooper CT-1409, "Echo" was presumed dead when a BX-series droid commando detonated the Republic's stolen shuttle on the platform outside the facility. As the Jedi and their clone troopers escaped across Lola Sayu's treacherous terrain, they were attacked by anoobas and droids led by Sobeck. General Piell sustained fatal injuries from an anooba, but before succumbing to his wounds, he whispered his portion of the Nexus Route information to Jedi Padawan Ahsoka Tano. Ahsoka Tano later killed Sobeck while he attempted to throw Tarkin into a lava gorge. The group reached the rendezvous point and were extracted from the planet by a Republic Low Altitude Assault Transport gunship.
Following the Clone Wars, a droid led a Separatist holdout at the Citadel. However, the droid in command of the garrison of battle droids malfunctioned, adhering only to its final directive from the previous war. It broadened its target range to include all Force-sensitives. Eventually, the droid held a Force-sensitive youngling captive within the prison, leading to a battle where a Jedi Warrior liberated the child. By 9 ABY, Unga Toba was serving a twenty-five year sentence, presumably at the Citadel, for unauthorized computer access.
The location made its debut in the eighteenth episode of Star Wars: The Clone Wars third season's, "The Citadel", which aired on February 18, 2011. Design and concept artist Tara Rueping created the design illustration of the Citadel. The Citadel's appearance was intentionally designed to resemble the Death Star's surface when viewed from a distance. The animation sequence depicting Jedi Masters Obi-Wan Kenobi and Even Piell emerging from the ventilation shaft was originally filmed on top of the Citadel tower but was later relocated to the landing area behind the tower with minimal changes. The monitoring devices lining the hallways of the Citadel were inspired by similar devices aboard the DS-1 Orbital Battle Station in the film, Star Wars: Episode IV A New Hope.