Spina Piccola, included in the museum tour, is intact, except for the wooden drawbridge, later replaced by a wall and designed to defend the barn, and the old citrus grove, provided with a special Arab inspiration irrigation system.
The tower, with a square base and built directly on the rock with carparo blocks, has a stern and dignified appearance. It spreads over two floors and it's crowned on the slightly overhanging parapet.
Each opening is defended by a machicolation. The entrance arch, which opens onto the boundary wall, is surmounted by a machicolation which can be accessed by a double staircase set against the fence from the inside. On the same side of the lama towards Spina Piccola, there are two more caves, in the citrus grove inside the walls of the tower. Here thereis another cave, not be visited, as used as a cistern.
The latter cave appears an unusual environment because of massive proportions with two central columns supporting the arches. The original function is hard to read because the cave was further dug to allow for greater reserve of water. In addition the walls are covered with a thick layer of "hydraulic mortar" that makes it watertight. It is assumed that originally was used as a place of worship.