The Tufs waterfall in Planches-près-Arbois in Jura forms a real ‘tuffière’ made up of limestone concretions with an unusual appearance. These concretions took the form of stepped promontories causing a succession of more or less high, wide and dense waterfalls. These concretions - from the Latin ‘concrescere’ i.e ‘to become solid’ - correspond to a thickening due to an accumulation of material from a water flow point in a karstic environment.