The Bạch Đằng River runs north of Haiphong and is one of the most historically significant waterways in Vietnam. Three separate naval battles fought here — in 938, 981, and 1288 — broke successive invasions from China and Mongolia, and effectively founded the modern Vietnamese state.
The actual battle sites are now broad mudflats and shrimp farms rather than dramatic scenery, but a small monument and museum on the south bank near Thuy Nguyen tells the story with archaeological finds (including some of the ironwood stakes recovered from the riverbed) and a few period reconstructions. It is a half-day trip from Haiphong, best combined with a stop at the more atmospheric temple of Tràng Kênh nearby.