The Honghe Hani Rice Terraces are the system of Hani rice-growing terraces located in Honghe Prefecture, Yuanyang County, Yunnan, China. The terraces' history spans around 1,200 years. The core area of the terraces is located in Yuanyang County. The total area measures 1,000,000 acres or 16,603 ha. A terrace is a piece of sloped plane that has been cut into a series of successively receding flat surfaces or platforms, which resemble steps, for the purposes of more effective farming. Graduated terrace steps are commonly used to farm on hilly or mountainous terrain. Terraced fields decrease both erosion and surface runoff.