The Sichuan Basin (Chinese: 四川盆地; pinyin: Sìchuān Péndì), or Szechwan Basin, is a lowland region in southwestern China. Despite its historical name, it is not only synonymous to Sichuan province, comprising its central and eastern portions as well as part of Chongqing Municipality (which itself was, until 1997, politically part of Sichuan). Due to its relative flatness and fertile grounds, it is heavily populated with a population of more than 100 million. In addition to being a dominant geographical feature of the region, the Sichuan basin also constitutes a cultural sphere that is distinguished by its own unique customs, cuisine, and dialects. It is also called the "Red Basin." It is famous for rice cultivation.