Military Correctional Facility-R-156 (MCF-R-156) was a rock quarry on Raydin III, converted into a military prison by the Confederate Marine Corps. It was in use during the Guild Wars to punish imprisoned soldiers with hard labor, working in a rock quarry that the Confederacy had acquired, said quarry's structures (a kitchen and mess hall) being acquired as well. Its features included at least three barracks equiped with sonic showers. Its inmates were drawn from various branches of the Confederate Armed Forces, including the Confederate Marine Corps, the Colonial Rangers and the Colonial Fleet. The prisoners were poorly fed, one such course being the "squib special."
The quarry itself was located at the end of a narrow canyon with steep slopes on three sides. The process used to mine the rock was primitive by 25th century standards and dangerous for the inmates—presumably part of added punishment. Explosives were used to seperate the rock from the mountain above.
In mid/late 2488, a number of problematic prisoners, such as Tychus Findlay and Sam Lassiter, had been sent here. They were subject to a reign of terror by Sergeant Bellamy until Findlay arranged for Bellamy's death, managing to avoid punishment for this deed.