The characteristic terroir of Châteauneuf comes from a layer of stones called “galets” (pebbles). The rocks are remnants of Alpine glaciers that have been smoothed over millennia by the Rhône. The stone retains heat during the day and releases it at night which can have an effect of hastening the ripening of grapes. The stones can also serve as a protective layer to help retain moisture in the soil during the dry summer months.