Củ Chi tunnels The Cu Chi Tunnels are an underground defense system located in An Nhon Tay commune, 69 km northwest of Ho Chi Minh City. This system was dug by the Viet Minh resistance forces and the National Liberation Front of South Vietnam during the Indochina War and the Vietnam War. The tunnel system includes a medical clinic, numerous living quarters, kitchens, storage rooms, offices, and an underground network of tunnels approximately 250 km long, with ventilation systems located among the bushes. The Cu Chi Tunnels were built at the end of the Ho Chi Minh Trail, in an area known as "steel land" to commemorate thẻ unwavering defensive spirit of the local people and soldiers. During the Tet Offensive of 1968, the South Vietnamese Liberation Army launched attacks on central Saigon from this tunnel system.