05DAYS- 04NIGHTS. Can Tho is the fifth largest city in Vietnam, and the largest city in the Mekong delta. It is noted for its floating market, rice-paper-making village, and picturesque rural canals. The tunnels of Cu Chi are an immense network of connecting underground tunnels located in the Củ Chi district of Ho Chi Minh City (Saigon), Vietnam, and are part of a much larger network of tunnels that underlie much of the country.