| Léez→ Adour→ Atlantic Ocean|
The Larcis (Occitan: Arsís) is a river in Southwestern France. It is a right tributary of the Léez, originating from the Vic-Bilh in the east of the Pyrénées-Atlantiques.
It joins the Léez in Lannux, in the French département of the Gers.
It shares its name with a tributary of the Estéous. The name of the Arcison, a left tributary of the Layon, is related.(L) Lizo,
(L) Léès, from Saubole.