From central Piazza della Repubblica and adjacent Piazza del Duomo, walk along Via Garibaldi then bear left along Vietata l'Affissione or Sdrucciolo del Castello, two pretty alleys and staircases that stagger uphill to this ramshackle castle. Former military barracks, it takes its name from the piagnaro (stone slabs) that were once widely used to roof Lunigianese buildings.
Views across town from the castle are impressive and inside is a small museum showcasing primitive stelae statues found nearby. No one knows exactly what these stelae, which have been found throughout the Lunigiana, were for – most depict male and female idols and date from around 3000 BC.