The Hien Luong Bridge crosses the Ben Hai river, the line that became the de facto border between North and South Vietnam from the Geneva Accords of 1954 until reunification in 1975. The original steel bridge survives alongside a wider modern one on Highway 1. There is a museum on the southern bank with photographs, the propaganda loudspeakers, and the dividing line painted across the deck.
The site is small but it is the place where the country's twentieth-century division is at its most legible. Pair it with a visit to Vinh Moc, which is on the same road north of Dong Ha.