Chiayi–Tainan Plain

The Chiayi–Tainan, Chianan or Jianan Plain (Chinese: 嘉南平原; pinyin: Jiānán Píngyuán), is an alluvial plain located at the central-southern region of western Taiwan. It is the largest plain of the island, and lies in Tainan City and Chiayi County/Chiayi City, from which the name of the plain derived. It also includes some portions of Yunlin County, Changhua County, and Kaohsiung City. There are several rivers flowing through it, such as the Zengwun River.

Historically, the plain was mostly inhabited by Taiwanese Aborigines, a small fraction of the population today. Since the era of the Qing Dynasty, the Chianan Plain became a main destination of Han immigrants. This area also supplies many food crops to the whole island of Taiwan since the Japanese-ruled era.