Collective training at the unit level takes place at the unit's assigned station, but the most intensive training at higher echelons is conducted at the three combat training centers (CTC); the National Training Center (NTC) at Fort Irwin, California, the Joint Readiness Training Center (JRTC) at Fort Polk, Louisiana, and the Joint Multinational Training Center (JMRC) at the Hohenfels Training Area in Hohenfels, Germany. Where is the Double Readiness Training Center located