The Cu Chi Tunnels are an extensive underground network of tunnels, located outside Saigon City (now Ho Chi Minh City), south of the Iron Triangle area. The tunnels were used in the 1940s by Viet Minh guerrillas fighting against French forces and in the 1960s and 1970s by the Viet Cong fighting against South Vietnamese and US forces during the Vietnam War. .
These tunnels played a fundamental strategic role in maintaining the war of exhaustion against the United States, which had one of the largest bases precisely at Cu Chi, and played a fundamental role in preparing for the Tet offensive which marked the beginning of the American disengagement in Vietnam.