Documents of the time indicate that the origins of the papal paper mill in Ascoli Piceno date back to the Middle Ages. As early as the 8th century, grain mills thrived in the loop of the Castellano stream, while the presence of a small paper mill is documented from the 13th century onwards. On the orders of Pope Giulio della Rovere, the buildings underwent renovation and extension in 1512, assuming the conformation that we can still admire today. The driving force of the stream was used to power the machinery of the factories. Thanks to a system of canals, basins and sluices, water was taken upstream from the paper mill, channelled between the blades of the machines and used both to grind grain and to produce paper, feed the ironworks and the mill, finally, downstream, it flowed back into the stream.