The Cu Chi Tunnels are an extensive network of underground tunnels located near Ho Chi Minh City, Vietnam, used by the Viet Cong during the Vietnam War. These tunnels served as a strategic asset for guerrilla warfare, allowing fighters to move stealthily, store supplies, and hide from U.S. and South Vietnamese forces, reflecting the increasing escalation of U.S. involvement in Vietnam and the innovative tactics employed by the Viet Cong in response to that involvement.