The Gilrain River System
The Gilrain River (Star-wanderer) begins in the White Mountains, some forty miles south of Min-Rimmon in Western Lebennin in southern Gondor and eventually flows into the River Serni above Linhir. The Gilrain has two tributaries the Serni and one small unnamed stream. The Gilrain forms the boundary between Gondor and Lebennin.
The River Serni begins beneath the eastern White Mountains, and flows southwestward through Lebennin until it meets the River Gilrain at Linhir.