Balor

Balor is likely a country or kingdom in the land of Albion. It is located beyond the Mountains of Isgaard roughly a day's ride from Camelot. Conjecture of its existence is based on the names of the Forest and Caves of Balor, which both occupy the same tract of land.

History
Arthur once journeyed to the Forest and Caves of Balor to retrieve a Mortaeus flower. He encountered the sorceress Nimueh along the way and was nearly killed when she lured him into a trap (The Poisoned Chalice).

Trivia

 * It is possible that Nimueh's Cave was located in this area, as she seemed to know it well enough to guide Arthur (The Poisoned Chalice).
 * Balor was an one-eyed giant in Irish mythology and leader of an evil race, perhaps an inspiration for these dark lands.