A humble district of Qo'noS in which General Martok was born and raised, whose low standing nearly kept him out of the Klingon officer class.
Martok speaks of the Ketha Lowlands in Once More Unto the Breach. His family had lived there for generations as loyal soldiers of the Empire, but none had ever been an officer, and the region carried no weight with the great houses.
When the young Martok applied to become an officer, the application was struck down by Kor, who would not accept a man of such low birth. With that mark on his record Martok could not even enlist, and he spent years as a civilian labourer on a general's flagship until he won a battlefield commission.
The grudge colours his treatment of the aged Kor throughout the episode. A Ketha Province on Qo'noS, described as uninhabited, also appears in the film Star Trek Into Darkness as the hiding place of Khan.