The Cascade de Saint-Cassin is located on the foothills of the Massif de la Chartreuse. The stream flows almost vertically into the Hyères, and is thus completely separate from the cliff.This particularity is a key reason for the popularity of the waterfall, and has made Saint-Cassin known to walkers. Famous writers, such as Jean-Jacques Rousseau, Lamartine and even Georges Sand have marvelled at this natural wonder.