The Great Tenasserim River or the Tanintharyi River is a major river of southeastern Burma. It flows through the Tanintharyi Region, past the town of Tanintharyi, and enters the sea at Myeik (Mergui).
The river rises from the Tenasserim Range at an altitude of 2,074 m (6,804 ft), and flows into the Andaman Sea.
The region formed by this river is also known as Tenasserim, or Tanintharyi in Burmese. It is in a constricted coastal region in southeastern Myanmar (formerly Burma), which borders Thailand on the east and the Andaman Sea on the west.
While non-indigenous fruit trees and other traces of a large population that once occupied the river banks are evident, the ethnic groups who live in this river valley are the Karens in the west and north, Thais in the south, and Burmans who speak a distinct dialect of Burmese.
