The Venetian Castle of Assos is located at the top of the peninsula of Assos and is the largest of the two castles in Kefalonia. It was built by the Venetians in the 16th century on the west coast of the island to protect the village of Assos from pirates.
Construction began in 1593 under the supervision of Ambrosius Cornelius, according to the sign outside from the main gate. Requests were made by the Kefalonians to the Venetian Senate for the establishment of a new fortress in 1584, as the Castle of Agios Georgios could not defend the entire island.
The fortress was of great strategic importance and made Assos capital of the north side of the island. Today, there are only remnants of the wall and other parts of the castle, as well as the church of St. Mark.