Cu Chi, which is about 30km from the north-west of Ho Chi Minh City to visit an incredible underground tunnel network constructed by Vietnamese fighters during the long struggle for independence. Cu Chi tunnels were used as the base from which the Vietnamese mounted their operations of the Tet Offensive in 1968. The Cu Chi tunnels consist of more than 200km of underground tunnels. This main axis system has many branches connecting to underground hideouts, shelters, and entrances to other tunnels, the tunnels are between 0.5 to 1m wide, just enough for a person to crawl along. Later on, Proceed to Tay Ninh, the head quarter of Cao Dai region founded on 1926. On arrival we attend the fantastic mid-day mass when the followers fill the hall wearing colored robes, a symbol of the curious combination of the Confucianism, Taoism, Christianity and Buddhism. Overnight in Ho Chi Minh City.