There may had been a preexisting building, but the castle that exists till today above the city of Vonitsa looking at Amvrakikos bay, was built around 1070 by the Venetians that were given permission by the Byzantines to build the fortress and take advantage of the harbor.
The castle is perfectly adapted on the cliff, taking advantage of the uneven ground, standing in complete harmony with the landscape but also very well protected by the attacks. Except the walls and the battlements, inside the castle you will see a cyclic temple dedicated to Agia Sophia. In 1922, a Royal Decree established the castle as “dominant byzantine monument”.