The Site is made up of two conservation areas, Nianhu and Changhaizi, that lie within the larger Huize Black-necked Crane National Nature Reserve in the central Wumeng Mountains in south-west China. The biodiversity is rich, with threatened species such as greater hog (Arctonyx collaris), Siberian crane (Grus leucogeranus) and scaly-sided merganser (Mergus squamatus). The other main species of conservation interest is the eastern population of black-necked crane (Grus nigricollis), which is the only crane that live all year round on the Yunan-Guizhou Plateau in which the Site is found. The Site is largely composed of seasonally flooded agricultural land, the Changhaizi reservoir, and the Nianhu reservoir which after 60 years of ecological succession has transformed into a near-natural lake wetland. The marshes in the Nianhu reservoir, the surrounding warm temperate coniferous forests, sparsely distributed scrubs, and agricultural land together offer essential habitat and food resources for the black-necked crane and other birds.