The royal prison, situated in Sundari on Mandalore, functioned as a prison. Notably, it was constructed to hang from the roof of the city's bio-dome. Duchess Satine Kryze found herself incarcerated within its walls on two separate occasions: first, when she endeavored to reveal Prime Minister Almec's illicit black market conspiracy, and subsequently, during Death Watch's violent coup.
Following his defeat and subsequent capture by the Mandalore resistance during the Siege of Mandalore, Almec was himself imprisoned in the very facility he once oversaw. While undergoing interrogation by both Ahsoka Tano and Bo-Katan Kryze, Almec met his demise at the hands of Gar Saxon, who sought to silence him and prevent any divulgence of information pertaining to Maul. Kryze gave chase to Saxon throughout the prison building, but Saxon successfully evaded capture.