The Red River Delta (Vietnamese: Đồng Bằng Sông Hồng, or Châu Thổ Sông Hồng) is the flat low-lying plain formed by the Red River and its distributaries merging with the Thái Binh River in northern Vietnam. The delta has the smallest area but highest population and population density of all regions. The region measuring some 15,000 square km is well protected by a network of dikes. It is an agriculturally rich area and densely populated. Most of the land is devoted to rice cultivation. Eight provinces together with two municipalities, the capital Hanoi and the port Haiphong form the delta. It has a population of almost 23 million. The Red River Delta is the cradle of the Vietnamese nation. Water puppetry originated in the rice paddies here. The region was bombed by United States warplanes during the Vietnam War. The region was designated as the Red River Delta Biosphere Reserve as part of UNESCO's Man and the Biosphere Programme in 2004.
