The castle of Santo Stefano d'Aveto was built in a strategic position along the route that connected the Ligurian coast with the Po valley through the Apennine passes.
The first documentary mention dates back to 1164, with the transfer of the fief of Santo Stefano and its castle by Emperor Frederick Barbarossa to the Malaspina family.
The fortress later passed under the ownership of the important Genoese families of the Fieschi and then the Doria, to whom it belonged until the suppression of the Imperial Feuds in 1797.
The castle today presents itself in the form of the transformations carried out in the 16th century to counter the effect of the artillery that spread during that period. The shape is that of an irregular pentagon, with narrow, wedge-shaped bastions, which were entered via drawbridges. In the centre of the fortress, the small parade ground is still visible.