Erui

The Erui (S. "First River") was the tributary of the Anduin which marked the boundary between Lebennin and the southern extremity of Anórien.The Erui was shallow and unnavigable. It possessed several fordable points, but only one bridge, at Minas Arthor, where it was crossed by the Rathon Gondor. This crossing was the site of the battle that decisively ended the oppressive reign of Castamir the Usurper in T.A. 1447.