Orukhan is a large lake on the western edge of the Northern Hordelands. Much of the water feeding into this lake comes from lake Radullu. This smaller, unnatural lake, fed by a watery rift to another world is above Orukhan on a high plateau. The unusual make-up of this plateau speaks of either divine doings or tainting from Chaos. Ancient history says that in the Creation War, a primordial named Sarseg opened the Radullu Rift from atop this plateau. Later when the Covenant general Silvanus succeeded in submerging the rift's other end (on the planet Throndar), it led to a river of water spilling across the plateau and cascading over its sides. This rift created lake Radullu and over the ensuing decades increased the size of lake Orukhan; and had far-reaching effects deep into the Troll Bogs.
Before the opening of the Radullu Rift, Orukhan drained east into the bay Tarag-Khâlu. This was by low-volume cascades. After the rift's opening, the volume of water spewing out turned some of these into great waterfalls. The lake expanded in size, finding outlets to the southwest; leading to the development of the Engargin mires.
In the northern reaches of Orukhan is the island Hraenar. In the Lith-Crillion Era, the settlement Aphenôrî was built there. The upper part of Orukhan, north of Radullu, is territory of the Witch Horde. The southern part is largely wild and dangerous with its proximity to the great troll-infested swamp Engargin.