Known in Thai as Maenam Kok, this scenic 130-kilometre long waterway runs through the heart of Chiang Rai. The river is a major transportation artery from neighboring Chaing Mai province, especially the town of Tha Ton (180 kilometres north of Chaing Mai provincial capital), whence tong-tailed boats make the 3-4 hour journey every day at 12.30 PM (Chaing Rai-Tha Ton: 10.30 AM). The river passes several hilltribe settlements and elephant camps from where jungle treks originate.