The construction of the St. Charles Tower, just beyond the mouth of the river Palma, dating to 1639 by Carlo Tomasi, first Duke of Palma, who obtained permission from Philip IV of Spain and had defensive purposes because of the continuous pirate raids Palmese on the coast.

 The fort was equipped with weapons, war gear, and a sufficient number of soldiers.

 It stands on a square body with a base shaped like a truncated pyramid. There are signs that indicate the presence of a drawbridge and shelves on which they were to rest the machicolations.
 
 Next to the tower was built a small church, which no longer exists, with the title of Most Holy Rosary, led by a chaplain, for the commissioning of soldiers. The defense features were maintained until 1820.