The western side of the islet housed a small harbour and warehouses for the tuna fishery. Work on its construction began in 1580 with stone material from the ruins of an ancient Byzantine monastery nearby. By 1595, the tower was already operational with a garrison of soldiers. Its cannons positioned at the top deterred landing operations by pirates for the supply of drinking water.

Its visibility was excellent and could reach up to 18 km, especially on the eastern shore: in the first half of the 17^th century, the tower succeeded in preventing a French fleet from landing there.

About 13 metres high, the tower had a domed main chamber (the residence of the garrison captain) with a central stone column and a fireplace. There is also a cistern in the lower part and a terrace with cannons, three gun ports, two sentry boxes and a latrine in the upper part.

A wooden staircase led to the entrance, located approximately 5.40 metres above the ground.  For its construction, large white limestone blocks from some important monument in the city of Nora were used as well. A few metres from this building one can see the ruins of a Byzantine monastery (7^th century AC) and a tuna fishery from the 1500s that were demolished during the First World War.