Almas Sith fortress

This fortress on the planet Almas in the Cularin system was created 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. The tower was once part of a larger dome-like structure, which was destroyed during the New Sith Wars. The fortress was impervious to blaster fire, so remained.

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 is such a strong focal point for the dark side, even non-force users feel strange when they come within two thousand kilometers of the tower.

The fortress laid abandoned for centuries before the jedi Kibh Jeen came to it and fell to the dark side. Jeen was eventually defeated by the jedi, and the Almas Academy was created to watch over the fortress. The Academy's founder, Nerra Ziveri, spent time attempting to probe its mysteries.

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.