II Corps tactical zone

During the Vietnam War, the Army of the Republic of Viet Nam (ARVN) defined II Corps tactical zone (II CTZ) as central Vietnam, including both the lowlands and the Central Highlands. It covered nearly half the land area of South Vietnam.

U.S. equivalents
Conventional American forces in II CTZ were under I Field Force Vietnam, headquartered at Nha Trang. 5th Special Forces Group headquarters were also in Nha Trang