The origins of the Opificio Cartiera Papale of Ascoli Piceno date back to the Middle Ages. The legal documents of the time testify to the activity of the mills for grinding grain in this reach of the Castellano river early as the eighth century, and the presence of a small paper mill since the thirteenth century. In 1512, at the behest of Pope Julius della Rovere, the buildings are refurbished and enlarged and Papale Paper Mill has the structure that we see today. The driving force of the river was used to activate the machinery of mills. The water, taken upstream of Paper Mill, thanks to a system of channels, tanks and closed, is conveyed between the blades of the machines. It provides the energy for grinding grain, for the production of the paper, to feed the ironworks and the crusher; downstream, flows back into the river, integrated and clean.