Gunsan Geumgang Estuary Bank (금강하구둑(군산))

Gunsan Geumgang Estuary Bank is a 1.84-kilometer earthen-and-concrete dam blocking the mouth of the Geumgang River where it meets the Yellow Sea, completed in 1990 to control salinity intrusion and provide agricultural water to the surrounding plains. Today the dam doubles as a tourism strip — a long pedestrian causeway with sweeping views back upstream toward Gunsan and out to sea, and an attached migratory bird observatory that fills with whooper swans, geese, and ducks every winter. The bird-watching season runs November through February. A small natural-history museum on site interprets the estuary ecosystem with bilingual panels. Free entry. Best at sunset in summer or for bird-watching in winter.