The majestic Da River not only enters into poetry, but it also has the three largest hydroelectric plants in the country with a total power supply of about 25 billion kWh of electricity per year. Song Da today has become a vast lake of nearly 600 square kilometers, of which Son La hydropower reservoir is 224 square kilometers wide. Let's explore the river and the beauty of this beloved land. On the bed of Song Da lake, an attractive destination that tourists can hardly ignore is Quynh Nhai boat tour.