The Red River Delta is the flat plain formed by the Red River and its dis tributaries joining in the Thái Binh River in northern Vietnam. The delta 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 Hà Nội and the port Hải Phòng form the delta. It has a population of almost 19 million. The Red River Delta is the cradle of the Vietnamese nation. Water puppetry originated in the rice paddies here. The region was bombed during the Vietnam War.