Pontremoli, defined by Emperor Frederick II "key and door of the Apennines", is dominated by its castle. The Castle of Piagnaro, built around the year 1000, served as a control of the many roads on the surrounding passes, including the Via Francigena. The name of the castle refers to the sandstone slabs, the "piagne", used for housing. The fortification, divided into two levels, reveals different historical stratifications: the oldest core with a majestic keep and the next one dating back to the sixteenth century. Now restored, the castle houses the Stele Statue Museum since 1975, helping to keep alive the identity of the Lunigiana.
