The Hoa Binh Dam stretches nearly a kilometre across the Da River (also called the Black River) and stands 128 metres high — an astonishing piece of infrastructure completed in 1994 after more than a decade of construction with Soviet technical assistance. For years it was the largest hydroelectric project in Southeast Asia, with a generating capacity of 1,920 megawatts and eight underground turbine halls buried inside the mountain. At its peak it produced a third of Vietnam's entire electricity supply.
Visitors can tour parts of the complex, including tunnels leading to the underground engine room, the operation centre, and a small museum dedicated to the plant's construction history. An 18-metre statue of Ho Chi Minh stands at the top of the dam wall. When the spillways are opened during high water, the sight — and sound — is genuinely dramatic: white torrents plunging down the face of the dam with the mountains echoing behind. Entry costs around US$2. Arrive in the morning before tour groups from Hanoi arrive.
story: > The project flooded dozens of Muong and Thai villages in the Da River valley, displacing some 58,000 people. Many were resettled on poorer land. The drowned villages — with their temples, rice fields, and graves — still lie beneath the reservoir that powers a third of the country. During periods of drought, when the water drops, the outlines of old structures briefly reappear.