Sith Citadel

This grand Sith Citadel was built both above and below the planet's surface. The above-ground structure was a massive, inverted truncated pyramid constructed from dark stone. It hovered above Exegol, featuring a platform designed to lower people into the Citadel's underground levels.

Inside the Sith Citadel was a vast hall filled with statues of ancient Sith, including representations of figures like Locphet, Mindran, Sissiri, Felkor, and Naga Sadow. The Sith fortress also included an amphitheater containing the Sith throne, and at least one other room dedicated to medical activities like genetic experimentation and life support. The Doctrine of the Dyad was inscribed on the Citadel's walls, serving as a constant reminder of its significance to both the Sith Order and the Sith Eternal cult.

The Citadel on Exegol represented one of the earliest strongholds of the Sith, predating the era of Darth Noctyss.

During the Galactic Empire's reign, Darth Sidious commissioned the creation of two Sith wayfinders to navigate to the Citadel on Exegol. One was crafted for his personal use and kept within his throne room on the second Death Star, while the other was presented to his Sith apprentice, Darth Vader, who stored the navigational device in his castle on Mustafar.

After Sidious assumed power and subsequently disappeared from public view, he made preparations for the throne at the Citadel to become his permanent seat of authority. Simultaneously, the Sith Eternal initiated experiments involving genetic enhancement and cloning technologies in an effort to prolong, and ideally, permanently sustain Sidious's existence.

Following the Battle of Endor, Sith cultists selected the Citadel as their new base, believing that Moraband, once the Sith's greatest fortress, was too vulnerable to discovery. At some point, Sidious was resurrected and took up residence at the Citadel. From there, he directed the actions of Snoke, whom Sidious had created sometime before, both to assess Kylo Ren's worthiness to inherit the mantle of the new Emperor and to govern the First Order while Sidious schemed in secret.

Meanwhile, Jedi Master Luke Skywalker remained convinced that the conflict with the Sith was not resolved, despite Vader's redemption as Anakin Skywalker and Sidious's demise above Endor. He and Lando Calrissian embarked on a quest to locate the Emperor's wayfinders in hopes of pinpointing the Citadel's location on Exegol, where Luke believed he could finally end the Sith threat. Luke's search stalled on Pasaana, leading him to ultimately retreat into exile on Ahch-To after the fall of his nephew, Ben Solo.

In 35 ABY, Supreme Leader Kylo Ren journeyed to the Citadel with the intention of eliminating the resurrected Emperor, whom Ren perceived as a threat to his newly acquired power. However, Sidious persuaded Ren to reaffirm his commitment to hunting down the Jedi apprentice Rey, who was revealed to be Sidious's own granddaughter. In return for Rey's death, Sidious promised Ren control over the Final Order, a formidable fleet of Xyston-class Star Destroyers possessing the destructive capability to subjugate the entire galaxy into perpetual obedience. However, Ren was redeemed from the dark side through the combined influence of Rey, his dying mother, General Leia Organa, and a Force vision of his father, Han Solo, and reverted to being Ben Solo once more.

Using Ren's wayfinder, Rey arrived at the Citadel and confronted Sidious. Sidious revealed to Rey that his intention was never to kill her, but rather to have her kill him, enabling his spirit to transfer into her and transform her into the Empress. This would have allowed him to possess her body through a ritual learned from his master, Darth Plagueis. He threatened that if she refused, her friends would be killed, as the battle was designed as a trap to annihilate the Resistance by the Sith Eternal forces. As a redeemed Ben Solo appeared, Rey rejected Sidious's offer to become a Sith and, together with Ben, attempted to finally defeat the Dark Lord. Instead, Sidious exploited their dyad in the Force to rejuvenate his mortal form. From the Throne of the Sith, Sidious then unleashed a storm of power that nearly decimated the Resistance forces.

However, empowered by the voices of all the Jedi who preceded her, Rey stood her ground and defeated Sidious by redirecting his lightning back at him. The resulting shockwave obliterated the Citadel and its cultists, leaving Rey alone, where she effectively died. The explosion also brought an end to the conflict between the Sith and Jedi. Rey was revived by Ben, who used Force healing in conjunction with their dyad to sacrifice his own life for hers. Ben then died in the ruined Citadel, becoming one with the Force. Rey then departed from the ruins in Luke Skywalker's T-65B X-wing Red Five just as the majority of the Sith fleet crashed to the ground in ruins.

Subsequently, historian Beaumont Kin, who had served with the Resistance during the war and participated in the Battle of Exegol, returned to Exegol and led an excavation of the Citadel. The excavation process began in the months following the battle.