It is the country's 54th World Heritage site, 14th natural World Heritage site and the country's first and the world's second intertidal mud flat heritage site, according to a news release from the National Forestry and Grassland Administration.

"It fills in the country's gap of intertidal wetland heritage sites," the release said.

The Phase I site, covering most of the Yancheng Wetland Rare Birds National Nature Reserve, the Dafeng Milu National Nature Reserve and intertidal mud flats facing the Yellow Sea in the cities of Yancheng and Dongtai in Jiangsu province, is right in the middle of the East Asian-Australasian Flyway. Every year, thousands of migratory birds, especially shorebirds, make stopovers, breed or winter on the intertidal wetlands in the area.