Almas Sith fortress The Almas Sith fortress was located on the planet Almas in the Cularin system . It was built by the Sith Lord Darth Rivan . The 30 - meter - tall fortress was completely black , had no visible entrances or windows , and sensors were not able to probe it . Characteristics . The terraforming plant kaluthin created by Darth Rivan grew all over Almas except for a wide area around the fortress , creating a large desert with the fortress as a focal point . It was a very strong focal point for the dark side . The castle was plagued with mechanical traps which could not be detected with the Force or with advanced technological means . He would use Mandalorian iron , resistant to the Force and to lightsaber , to keep his most valued books , and for the floor of his lightsaber training room . He also designed the fortress so that his slaves / prisoners ( which included at least one Jedi ) would be unplugged from the Force , feeling absolutely lost and despaired . Darth Rivan wrote his autobiography in Sithese in the inner walls of his fortress . Rivan also kept the enslaved ghost of his apprentice Darsin in the crypt , with the eternal order of protecting the fortress . History . The tower was once part of a larger dome - like structure from which Rivan aimed to perform research on the Sith battlelord s . It did not have an apparent door , leading experts to believe that either it had a hidden one , probably underground , or that Rivan had some power to go through walls . However , during the New Sith Wars , the Jedi found Rivan and expelled him from the planet in the Battle of Almas . The structure was destroyed , but the inner tower , later known as the Almas Sith Fortress , proved impervious to blaster fire . Nevertheless , the Jedi left the planet , caring little about the empty fortress . Rivan ' s fortress and the planet itself were forgotten . After the Battle of Almas , the Cularin system was forgotten and the fortress laid abandoned for centuries until its rediscovery in 232 BBY . During her initial scouting , Reidi Artom noticed the fortress , but found it too creepy to approach it . She also noticed kaluthin still in the fortress area . She decided that this was more a Jedi affair that hers . In 188 BBY , Jedi Master Qornah and his Padawan learner Kibh Jeen came to the fortress to research it . Influenced by the dark side site , Jeen fell to the dark side , killed Qornah and began the Dark Jedi Conflict . Seven years later , Jeen was defeated by the Jedi , and the Almas Academy was built in the opposite face of Almas , to watch over the Sith fortress . Academy founder Nerra Ziveri , convinced that the fortress would be very important in the future of the galaxy , spent time attempting to probe its mysteries . Jedi comparing the dark side taint in the Fortress with the presumed dark side site known as Kaernor ' s Smile , in the same planetary system , always concluded that the Smile was not a dark side while the Fortress was . Any visitor felt " something strange " from more than miles from the Fortress ( The wasteland was bigger than that distance ) , and anyone without training in the Force was commonly unable to resist it . In the last years of the Old Republic , a group of dark side cultists calling themselves the Believers found subterranean entrances to the Fortress and used it as their base of operations for a time before being discovered by the Jedi . Shortly after the Invasion of Naboo , criminal Len Markus found the Sith artifact Darkstaff , which had been both possessed and feared by Darth Rivan . Markus tried to leave the Cularin system in a ship but , when nearing the orbit of Almas , his ship was shot by a Force lightning from the Almas Sith Fortress . As a result of this , the Darkstaff was damaged , Markus was presumed dead and the Cularin system disappeared for one decade , before reappearing just as suddenly . Soon afterward , the Jedi Order took control of the Almas Sith Fortress . The Almas Academy , in the other hemisphere of the planet , sent a team of Jedi both as research team and as guards against a possible attack from the Believers . The Jedi had not explored the whole fortress , as they have not discovered all the traps or the dark side taints it could have . Some twenty Jedi were there at any time . During the beginning of the Clone Wars , the Fortress was invaded by a team sent by Markus . These raiders intended to perform a Sith ritual to create battlelords in the crypt of the fortress , and at the same time repairing the damaged Darkstaff . In the process , they killed four Jedi guards and captured two others . They performed the ritual , but it was ineffective — instead of creating Battlelords , it absorbed the Force essence of the victims . The raiders left , leaving behind the bodies of the casualties . The raiders left three of the Jedi corpses in their guard post , but took the fourth one and used it as a bait for an ambush with gundarks , to cover their tracks killing any search team the Jedi could send . As the raiders performed their act during a sandstorm , most of the proofs were destroyed . However , Jedi illusionist Treibeiu , who was assigned to the fortress , kept in her memory the crime scene as she had seen it , and could use her powers to reproduce it — showing , for instance , wampa footprints . The Almas Academy sent at least three search teams to find the missing bodies . Almas Jedi Master Lanius Qel - Bertuk refused to send Jedi - only teams because the attack could have been thought to bait the most powerful Jedi in the Academy . The search was fruitful : At least two of the three missing Jedi were found , plus the bodies of the intended Battlelords , and proofs suggesting that the leader of the raid was slaver Phylus Mon . During the years following the Yuuzhan Vong War , members of the New Jedi Order were prohibited from venturing near to the fortress .