The best-preserved tower, is actually two towers in one (for location, see plan). The lower part is square and made of cyclopean stone blocks—large and irregular in shape—laid without mortar. Like the island’s eight other towers, this lower section is made of the same material as the perimeter wall and was bonded to it; the wall and towers were conceived and built as part of a single plan. The upper portion of this tower, however, was added later; it is semicircular and consists of small masonry blocks similar to the stonework of the Moslem castle on the north hill, indicating that it is medieval in origin.