Hanoi can be unquestionably said to belong to this class, for it is the capital of Vietnam while Ho Chi Minh City is the largest port and economic area of the country. Ho Chi Minh City, formerly Saigon, is located in southern Vietnam, one hundred kilometers south of the Mekong Delta on the right bank of the Saigon River, a tributary of the Tongnai River, and eighty kilometers southeast by air from Haikou. The city dates back hundreds of years frequently mentioned as a fishing village. Time after time, Ho Chi Minh City developed gradually into a busy and crowded commercial center and international trade port. Ho Chi Minh City became the capital of the Republic of Vietnam after 1955, and Hanoi was sooner or later acclaimed the official capital of the reconstituted nation after the war and the reunification of Vietnam in 1975.