Saemangeum

thumb|right|220px|A view of the Saemangeum Seawall thumb|Sinsi sluice gate of Saemangeum Seawall

Saemangeum () is an estuarine tidal flat on the coast of the Yellow Sea in South Korea. It was dammed by the government of South Korea's Saemangeum Seawall Project, completed in 2006, after a long fight between the government and environmental activists, and is scheduled to be converted into either agricultural or industrial land. Prior to 2010, it had played an important role as a habitat for migratory birds.