The tiered citadel rose from high ground at the end of a peninsula, surrounded on three sides by a lake fed by an irrigation canal. The structure of the citadel was reminiscent of the command towers of Lucrehulk-class Core Ships, themselves modeled on Neimoidian hive structures.
The lower ramparts of the citadel opened out onto an orchard of manax trees, and were defended by turbolaser cannons. A deflector shield generator protected the entire structure, and was powerful enough to stave off even orbital attacks.
During the Outer Rim Sieges, Gunray returned to his fortress following the targeting of his homeworld and the fall of purse worlds Deko and Koru Neimoidia. Escorted by a battle fleet of Federation warships, Gunray attempted to flee with as many of his possessions as he was able to loot from the citadel. However, the Republic anticipated this move, and launched a strike against the planet.
Republic forces, led by Jan Dodonna and Jedi Obi-Wan Kenobi and Anakin Skywalker, laid siege to the citadel, hoping to trap Gunray inside. Although the citadel was breached, the Viceroy made his escape in Lapiz Cutter, rendezvousing with General Grievous in orbit. However, he neglected to take with him a prized mechno-chair, which was later found by Anakin Skywalker and Obi-Wan Kenobi, the capture of which ultimately led to a hunt for Darth Sidious, the Dark Lord of the Sith, prior to the Battle of Coruscant.
Gunray's citadel was captured by the Republic forces during the Battle of Cato Neimoidia, when clone trooper X2 infiltrated the fortress with Jedi Master Ferroda and shut down the droid army.