An ancient parchment, part of the treasure of the Cathedral of Troy, drawn up in Biccari in 1122, allows us to date the period of its construction between 1116 and 1122.
The powerful cylindrical tower is made of irregular and faceted stones, cemented with clay mortar. 23 meters high, has an external diameter of about 13 meters and its walls, at the base, exceed the thickness of 3 meters.
Originally it was divided into four levels, one of which is entered through an external breach in the foundations, dating back to a fairly recent era. It was also equipped with a secret tunnel, now destroyed, which led the militia outside the walls of the country. The floors were supported by large beams stuck in the walls, on which crossed other less thick, equally thin, wooden floors. The original entrance was through a staircase still existing with which you reached the first floor. Windows, almost all of them walled up afterwards, are in every direction and on all floors.
The monument has been renovated and equipped with an internal staircase to connect the various floors; it is used for events and exhibitions.