High Quality Content by WIKIPEDIA articles! The Yancheng Coastal Wetlands stretch for nearly 600 km along the coast of central and northern Jiangsu province in China and spans five counties. The Jiangsu coast is the most extensive example of inter-tidal mudflat and saltmarsh coast remaining in China. The wetlands consist primarily of extensive inter-tidal mudflats, tidal creeks and river channels, saltmarshes, reed beds and marshy grasslands. Sea dykes have been built over the years and much of the natural habitat has been converted to other uses, although it retains its wetland character. Inside the sea dykes, large areas of salt pans, fish and shrimp ponds, reed farms, rice fields and irrigation and drainage canals remain important biodiversity conservation areas. The Yancheng coastal marshes were designated as a Biosphere Reserve under the UNESCO Man and Biosphere Programme in November 1992 and as a Northeast Asian Crane Reserve Network Site in March 1997.