Quynh Nhai: a valley under the lake

The Son La hydropower plant, inaugurated on 23 December 2012 after construction began in 2005, has six 400 MW turbines for a total of 2,400 MW. Its dam stands at It Ong in the former Muong La district. The reservoir behind it covers about 440 km² and holds about 3.1 km³, according to Wikipedia’s summary of the project data; a provincial feature gives a figure of about 9 billion m³, so treat volume figures with caution. The government portal said more than 20,000 ethnic households gave up homes and land for the project.

Quynh Nhai was one of the areas most changed. Its old centre is under the water, and the Thai communities that lived along the river were moved to new villages higher up. A memorial on an island honours those who gave up their land, and resettled families paddle out to it at Tet. The lake that resulted, with hilltops turned into wooded islands, is what visitors now come to see. It is not a wilderness; fish cages, floating restaurants and new resorts line parts of the shore.

Highway 279 crosses the lake on the Pa Uon bridge in the former Chieng On commune, now part of Quynh Nhai commune. The deck is 918 m long and the main pier 98.6 m tall, recorded as the tallest bridge pier in Vietnam, with 103.8 m from the old riverbed to the road. The area around the bridge has restaurants, hotels and a boat landing, and the bridge is a favoured place for sunset.

Onshore, the Nang Han temple, built in 2012 in the resettlement area of Muong Giang, and the Linh Son Thuy Tu temple form a spiritual and cultural site. Ban Bon has a hot spring and community tourism, and the Thai village of Phieng Lanh has revived a hair-washing festival. In June 2026 a provincial survey of the shoreline noted that the Prime Minister’s 2025 tourism plan lists the reservoir as a potential National Tourism Area, alongside proposals for floating solar farms on the water.

There is no airport in Son La with scheduled flights. Dien Bien airport is about 170 km from Son La town, roughly three hours by road, and Hanoi’s Noi Bai is the main gateway. Buses from Hanoi to Son La town were reported at 150,000 to 350,000 VND in 2024. From Son La town, a bus, a hired car or a motorbike covers the last stretch.

• Travellers coming from Hanoi just for the lake in a day. It is too far; combine it with Son La town or the road north.
• Anyone wanting untouched nature. The shore has fish farms, restaurants and new building, and more are planned.
• People unwilling to take a small boat whose safety standards they cannot check.
• Visitors in heavy rain or storms, when boat trips are unpleasant and roads around the lake slow.