"The Hall of Decessus, named after one of my better apprentice's; it was an old, underground, imperial facility. It was dedicated to the creation of terrible Sith Spawn and other horrors alike. Do you recall the Galactic News coverage of the weapons testing on Bengat?"
— Guntai Haj'ra to Sha'ira Luroon while sharing a cell in the Hall of Decessus, Dagobah.
The Hall of Decessus or otherwise known as Decessus' Hall was a large, underground, prefabricated imperial facility located on Dagobah. The construction was conducted by the Empire Reborn while in preparation of leaving the Dynali Sector. The facility was used for the creation, development and testing of Sith spawn, weapons of mass destruction and other gadgets utilized by Imperial and Sith personnel from the Disciples of Ragnos and potential affiliates. It was also alternately used as a secondary housing unit of imperial personnel and shared prison facility.
It was said that Lady Aranka's family resided there.