The tunnels of Củ Chi are an immense network of connecting underground tunnels located in the Cu Chi district of Ho Chi Minh City (Saigon). They are part of a much larger network of tunnels across the country.
The Củ Chi tunnels were used in several Viet Cong military campaigns during the Vietnam War, particularly the Tet offensive of 1968. They served as hiding spots during combat, as well as communication and supply routes, hospitals, food and weapon caches and living quarters for numerous guerrilla fighters.
The tunnel systems were of great importance to the Viet Cong in their resistance to American forces, and helped them achieve ultimate military success.