The spectacular Fortress of Castruccio Castracani stands on the top of the Sarzanello hill overlooking the medieval city of Sarzana and the plain of the Val di Magra, along the Via Francigena.

The oldest nucleus, documented from the 11th century, was modified between 1314 and 1328 by Castruccio Castracani and, in the 15th century, by order of Tomaso Campofregoso. The current structure dates back to the decision of Lorenzo De Medici to transform Sarzana into a fortified outpost in defense of the Florentine seigniory and entrusted the work to Francesco di Giovanni known as il Francione.

Seen from above, the fortress has a rhomboid shape due to the particular triangular walls equipped with towers at the top and to the massive construction protecting the entrance called ravelin. The structure, delimited by a moat in which the presence of water was not foreseen at the time, presents the keep in the center, consisting of four floors with a walkway at the apex, in addition to the various service areas useful for everyday life. In the lower part are the prisons and dungeons, perfectly preserved and practicable.

The fortress, still used today for military exercises, is open to the public and home to cultural events.