The residential area of Tresana is situated on a hill and overcome by the ruins of an ancient complex of castle relics which majestically dominate the small hamlet below. Most likely founded during the Longobard era, the castle was given by Federico Barbarossa to Obizzano Malaspina of Mulazzo in 1164. Kept in poor conditions up to the past century, the castle has a parallelepiped layout and is overlooked by the quadrangular tower still perfectly intact. It was given the name of "owner's residence" although it preserved several privileges such as the rights of the first-born male. This was done to prevent the dispersion of the property. Another privilege maintained was that of minting coins, which in the area was exclusively reserved to the Massa and Fosdinovo feuds.