This is an international-grade wetland situated at the estuary of the Zhengwen River. From the north, it starts at the Guosheng Lighthouse (Qigu Lighthouse) on the Dingtoue sandbank, the south bank of the south dike, and Qigu dike in the reclamation. To the south, it touches the Qingcaolun dike on the south bank of the Zhengwen River. In the east, it borders Guosheng Bridge along the Provincial Highway No. 17. In the west, it extends to the 6m depth contour in the waters. Totally, it occupies a total area of 3,218 hectares.
The Zhengwen River originates from the Alishan Mountain Range, with major distributaries including the Houku River, the Caoliao River, and the Guantian River, with a drainage area of about 1,176m2. The length of the main stem is about 138km. Located at the estuary of the Zhengwen River in southwestern Taiwan, due to the rich nutrients carried down from the upstream, the wetland comes an integrated habitat for all levels of living organisms. From October every year, the black-faced spoonbill flies from South Korea to spend winter here.