From Halopedia, the Halo wiki
Camp Patmos was a UNSC underground camp located on Chi Rho. The planet was under the command of Vice Admiral Jean Mawikizi and he had at least one division guarding the camp. The camp housed a large amount of offices and barracks, and played a major role in coordinating the UNSC's frontline defenses. The camp also housed enough Scorpions and Warthogs for a large division.
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