The Castle of San Terenzo is a fortification that stands in a dominant position over the seaside village of San Terenzo, a fraction of Lerici, in the Gulf of Poets.

The current castle was probably built in the fifteenth century by the inhabitants of the small village in order to protect themselves against the incursions of the Saracen pirates, the same 'Turks' from which the cave that opens into the rocky promontory on which stands the The building can be inscribed among the military works of the great defensive system developed by the Genoese Republic in the Gulf of La Spezia between the end of the 16th century and the beginning of the 17th century, an offshoot of the most imposing fortress of Lerici, which can now be reached walk from the Castle along the suggestive seafront promenade. Between the 19th and 20th centuries it was transformed into a barracks for sailors, soldiers and the financial police and was used as a photoelectric station complete with military personnel responsible for the security and defense of the Gulf. Today it has abandoned its original military strategic function and is the site of exhibitions and cultural events.