A hill district in the extreme north of the Tenasserim Division of Lower Burma, lying between 17° 17´ and 18° 41´ north and 96° 58´ and 97° 46´ east.

It includes the whole of the country between the Salween on the east and the Paunglaung range (the watershed between the Sittang and the Yunzalin and the Bilin) on the west.

On the south the boundaries are mainly arbitrary and not so well defined.