Called the Ama Basin, after the great Ama river that drains the region and empties into the Celestial Sea. This watershed includes the northern Koryaz Mountains and its forested foothills, and the taiga (evergreen forests) and swamps which stretch between the mountains and the fringes of the Land of Snow Demons.
Most of the indigenous humans of the Ama Basin fall into three nations, or tribal groupings: the Issacortae, the Pazruki, and the Wu-haltai. They are not nations in the political sense, so much as groupings according to appearance, language, and culture. Of the three, the Issacort tribal confederation is the most cohesive politically. On the opposite extreme, the many Wu-haltan clans form alliances only in times of need, and remain otherwise autonomous and often quite isolated.
There are a number of small native tribes besides the three nations. Some are recent immigrants from such nearby regions as the Plain of Horses and the Land of Snow Demons. Others, including primitive groups that still use stone and bronze tools rather than ones of iron, are of uncertain origin and seem not to be closely related to any known peoples. (Sometimes the korobokuru are classified as such a class of humans.) Many legends mention such tribes. Some people believe the tribes to be descended from the Ancient Lords, or Maraloi, who never used iron.
Some of the places of interest in the Ama Basin include: