CT-Tertium was a barracks built by the Galactic Republic in the military base Ground Base Seven on the planet Drongar during or prior to 30 BBY. The barracks housed Clone troopers stationed on the planet to fight against Separatist forces for control of the plant Bota which grew there. The barracks was the largest of three garrisons in ground base seven which was built on the edge of the Rotfurze Wastes, an area of blight. The Human surgeon Jos Vondar traveled to CT-Tertium in an attempt to meet CT-914, a clone stationed in the barracks who he had previously spoken too at Republic Mobile Surgical Unit 7 about the grief the soldier felt after the death of his comrade, CT-915. Vondar wished to apologize to the trooper for assuming that clones could not feel such emotions, but upon reaching CT-Tertium discovered that the trooper had been recently killed in an ambush.