The Kyll, noted by the Roman poet Ausonius as Celbis, is a 128-kilometre-long (80 mi) river in western Germany, left tributary of the Moselle. It rises in the Eifel mountains, near the border with Belgium and flows generally south through the towns Stadtkyll, Gerolstein, Kyllburg and east of Bitburg. It flows into the Moselle in Ehrang, a suburb of Trier.