We then headed to the tunnels of Cu Chi. The tunnels of Cu Chi are a network of connecting underground tunnels located in the C? Chi district of Vietnam, and are part of a much larger network of tunnels that underlie much of the country. The C? Chi tunnels were the location of several military campaigns during the Vietnam War, and were the National Front for the Liberation of South Vietnam's base of operations for the T?t Offensive in 1968.