Irregular in form of medieval bases with protruding corners partly raised in rebuilding the city after the riots and fighting during the Venetian occupation twenties XV. century. Top of the tower now has a panoramic viewpoint overlooking the city, the island and the sea. From the tower to the east stretches the city wall. Until now, a large part of it has been preserved until the remains Monastery of St. John and north to the Tower of bold or Gagliardi. The door in the wall of the tower were broken recently after raising the city park. There is already in the Middle Ages, the little church of St. Christopher, the patron saint, after which the tower got its name.