The Palazzo della Zisa,
built during the reigns of William I and II, is a three-storey building. In some
respects it is reminiscent of Egyptian and Mesopotamian building techniques,
being designed with an ingenious ventilation system to ensure that a current of
cool, moist air circulates continually throughout the building. The gusts of the
Sirocco are captured by the two lateral towers, and the currents of air they
create are channelled up and down by internal conduits. The air is cooled and
humidified by contact with water in the fountains and small channels cut in the
pavement of the large room on the ground floor. The hydraulic system was
connected with an artificial pool situated in front of the building, in the
centre of which stood a domed pavilion.
The central core of the building consists of two large rooms, one above the other (the Fountain Room and the Tetrastyle Room). The arrangement of the rooms bears some similarity to castles in Normandy, which have a large hall for receiving visitors (aula) and, behind it, the lords apartments (camera). The structural features are typical of Norman techniques for supporting tall buildings, while the shape and arrangement of stones in the vaulting, the mosaic decoration and the niches supported by columns reflect Byzantine influence.
Beside the Zisa are the ruins of an old bath house and a small palace church.
G. Caronia, "La Zisa di Palermo, storia e restauro", Bari ,1982
V. Noto, " Les palais et les jardins siciliens des rois normands", in : Trésor romans d'Italie du Sud et de Sicile, Toulouse-Caen, 1995 ( V. anche le schede di Fawara, Altofonte e della Cuba)
G. Cappellani & Melo Minnella, Palermo