About 75 wetlands in Korea are registered as scientifically significant. Along the coast line of the Yellow Sea, abundant tidal flats have developed, and there are many inland wetlands. The inland wetlands are divided into river and mountain wetlands. Typical river wetlands can be found along Nakdonggang. Unlike many other rivers in Korea, Nakdonggang has a relatively gentle channel upstream, which provides ideal conditions for the formation of river wetlands. Especially flood-plain type wetlands (e.g. Uponeup) are well developed in Nakdonggang drainage basin. On the other hand, mountain wetlands formed on gentle slopes at the top of mountains. 15 wetlands (10 inland wetlands and 5 coastal wetlands) are registered as protected area in 2007, and five (Daeamsan Yongneup, Uponeup, Jangdo wetland, Suncheonman, Boseong-Beolgyo tidal flat) among them are endorsed by the RAMSAR convention on wetlands.