Dead Castle was a castle situated on Dennaskar. Previously, it functioned as the governing center for the planet's inhabitants. However, following the world's depopulation, the Galactic Empire seized control of the structure, transforming it into a military installation. Prior to the Battle of Endor, Tay Vanis experienced a crash landing on the planet while piloting his X-wing starfighter. After his capture, Darth Vader arrived on the planet and subjected the man to torture, ultimately reducing him to a persistent vegetative state.
Subsequently, Vader confined Vanis to a small, secured chamber, sharing the knowledge of his location only with the local garrison. To the remaining Imperial forces, Vader intentionally propagated the false impression that Vanis remained at large, serving his own strategic objectives. This fabricated information allowed the Dark Lord to occupy several of his more zealous officers, while simultaneously diverting numerous rebel operatives who were actively searching for an individual already under Imperial custody. Vader appointed an Imperial officer to oversee the castle and strategically positioned a prerecorded hologram near the entrance of Vanis's locked room, intended to mock anyone who successfully located the planet where Vanis had crashed.
Around 3 ABY, Luke Skywalker, Leia Organa, and C-3PO journeyed to the planet and infiltrated the castle, where they discovered Vanis's comatose form. Vanis's droid, LE-914, initiated a self-destruction sequence in close proximity to her master, resulting in their mutual demise. As the Rebels made their exit from the castle, Skywalker deliberately sabotaged the building's primary power hub. As they made their escape aboard the Millennium Falcon, the castle underwent a catastrophic explosion, creating a lasting tribute to the Rebel informant.