The Vaucluse ( ; in classical norm or Vau-Cluso in Mistralian norm) is a department in the southeast of France, named after the famous spring, the Fontaine-de-Vaucluse. The name Vaucluse derives from the Latin Vallis Clausa (closed valley) as the valley here ends in a cliff face from which emanates a spring whose origin is so far in and so deep that it remains to be defined.