洞庭湖
The earliest rice paddies yet discovered in the world were in the Liyang plain, which was then on the western edge of Dongting lake. The state of Chu occupied the region in the Eastern Zhou period, and its territory there was taken over by Qin in the 3rd century BCE. During the Han Dynasty, Yunmeng Marsh ( literally "Great Marsh of Cloud Dream"), which lies to the north of Dongting Lake in Hubei Province, served as the main flood-basin of the Yangtze. The rich sediment of the marsh attracted farmers. Embankments were built, keeping the river out, and the Dongting Lake area south of the Yangtze gradually became the river's main flood-basin. The Han state was actively involved in the colonization of the region, maintaining dikes in Liyang to protect farmland from flooding.