Known in Thai as Maenam Kok, this scenic 130-kilometr long waterway runs through the heart of Chiang Rai. The river is a major transportation artery from neighbouring Chiang Mai province, especially the town of Tha Thon (180 kilometres north of Chiang Mai provincial capital), from whence long-tailed boats make the 3-4 hour journey every day at 12:30pm (Chiang Rai-Tha Thon: 10:30 am). The river passes several hilltribe settlements and elephant camps from where jungle treks originate.