Cu Chi Tunnels is a vast network of underground tunnels located in the Cu Chi district of Ho Chi Minh City (formerly known as Saigon), Vietnam. The tunnels played a significant role in the Vietnam War, as they were used by the Viet Cong as hiding spots during combat and to move supplies and troops.

The tunnels stretch over 120 kilometers in length and were constructed by the Viet Cong in the 1940s. They were initially built as a means to hide from French forces during the First Indochina War, and were later expanded during the Vietnam War.

The tunnels were designed to be a self-contained underground city, with living quarters, hospitals, storage facilities, and even theaters. The tunnels were also equipped with booby traps, and were well-ventilated to allow the Viet Cong to remain underground for long periods of time.

Today, visitors can tour a small section of the tunnels, which have been preserved and turned into a museum. Visitors can crawl through narrow passageways, see the living conditions of the Viet Cong soldiers, and experience the claustrophobic nature of the tunnels. The Cu Chi Tunnels have become a popular tourist attraction in Vietnam, drawing thousands of visitors every year.