Heading for Lou Rey coming from Nimes or Montpellier, take direction Alès. Fromf there, follow the signs Mende passing la Grand Combe.

Cross  le Collet de Dèze and pass the bridge over the Dourdon-river. Turn your car at the school-parking, immediately after the bridge (at your left).
Recross the bridge and take the first road to the left, which leads you to Lou Rey (4km). 

Coming from Florac, cross the bridge and take the first road to the left, to Lou Rey 
It is a quit narrow and sinuous mountainroad, please drive prudently (those who goes up has priority).