The Langwell was one of the two rivers, along with Greylin, that met in the northern Vale of Anduin to form the beginnings of the Anduin River. The Langwell flowed east from the Misty Mountains.
In T.A. 1977, Frumgar led the Éothéod from the middle to the upper part of the Vale of Anduin to escape from the growing shadow of Dol Guldur, and to take advantage of the fall of Angmar in 1975. Upon their arrival, they built their capital city of Framsburg (named after Frumgar's son Fram) between the Langwell and the Greylin. The Éothéod left the vicinity of the Langwell in T.A. 2510 when they became the Rohirrim, settling in Rohan.