The Normans came to Sicily as mercenaries, but quickly adapted to the local Arabic culture to the point that they even began aping their architectural style as in the case of the La Zisa palace.

King Guglielmo I earned the epithet "Il Malo" ("The bad one") for being, according to his detractors, more interested in wine, harems, and luxury than politics. Around 1165 the king financed the construction of the summer residence of his court: the castle of the Zisa (from the arabic term "al-aziza," roughly translated as "the gorgeous"). The palace is designed entirely in Islamic-style architecture, featuring ogival archways, muqarnas, vaulted niches, and even a perfectly functional air conditioning system. The architect who designed the building used many devices to create a comfortable place to relax during the scorching heat of Sicily's summer. The castle faces north-east, so that the ample fornices in the first level could capture the temperate winds coming from the sea, and a large pool in front of the building, connected directly to the main hall's interior via a further decorated pool with flowing water, provides the necessary humidity to keep the air fresh. The remaining upper levels also feature a system of vent ducts connected with the lower vestibule, in order to create a constant air flow through the entire building. Finally, thick walls and small windows help keep a stable internal temperature.

The Zisa was completed by Guglielmo II, "Il Buono" ("The good one") and since that time it hasn't been modified substantially. For a long period of time La Zisa was abandoned, and the lack of maintenance seriously compromised the structure. However, in June 1991, after a deep restoration mission that lasted more than twenty years, one of the most suggestive and interesting treasures of the Arabic-Norman culture in Sicily was once again opened to the public.