The Rivil was a lesser tributary of the Sirion River. Its source was Rivil's Well in the highlands of Dorthonion, from which it flowed westward to meet the Sirion at the Fen of Serech.
During the Nirnaeth Arnoediad King Turgon retreated down the Pass of Sirion. His escape was successful because Húrin and Huor formed a rearguard that used the Rivil as a defense. The host of Angband bridged the stream with the corpses of their dead. Huor was slain beside the Rivil and Húrin was captured.
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Map of Beleriand and the Lands to the North"
J.R.R. Tolkien, Christopher Tolkien (ed.), The Children of Húrin, "The Battle of Unnumbered Tears", p. 59