The base used by Attuma Duum was in a hollowed-out asteroid near the Mid Rim moon Cavamina Minor. A large 30-story structure was attached to the wall, and pipes connected to the structure ran to five other facilities under domes. Attuma Duum had a domed control center under the stars with a throne-like chair. An escape hatch led to Class-6 escape pods. That dome had a room with turbines it it. Prisoners were held with their hands in force fields.
The whole site was protected from the other asteroids by deflector shields, but safety protocols provided back-up power. The base also had casinos and hangars.
Attuma Duum was using this facility to run his mercenary empire around 21 BBY and to profit from the galaxy-wide Clone Wars. Duum was passing information to both sides. One set of communications resulted in a battle near the asteroid field. Duum had used his bombers to place 600000 space mines. Duum passed on falsified information regarding a Confederacy of Independent Systems convoy to the Galactic Republic's Navy, and passed on information to the Confederate Navy about a Republic fleet which would be in the system. Both fleets reverted from hyperspace in the middle of the mine fields, and proceeded to fire on each other in the confusing circumstances before fleeing the system.
During the battle, Duum's two Force-sensitive captives, Aayla Secura and Shon-Ju escaped from their holding area and confronted the mercenary in his command center. His chief of security, Sabat was Force-tossed into a turbine, causing an explosion and killing the man. Duum dismissed his crew, sending them to the casinos. Duum revealed his cyborg body and directly fought Shon-Ju but was bested. Secura intervened to keep Shon-Ju from killing Duum, allowing the cyborg to escape. Shon-Ju then fought Secura, but she bested him in turn, causing the defeated man to run into the spreading flames. The damage caused eventually led to the destruction of Duum's base, but not before the principal players escaped. Duum's empire was then considered crippled.
This headquarters was introduced and then destroyed in Volume 5 of the The Clone Wars graphic novellas.