The castle of Salemi is one of the best preserved castles in Sicily. Inside, the library and the resurgence museum are housed. The castle has Norman origins and dominates the town with its trapezoidal shape and square, 20 meters high, corner towers, and a cylindrical tower.
The castle was built by Norman King Roger around 1077 to the site of Roman-Arab fort. Frederick II altered it in the 13th century.
In 1441, on December 11, in the castle of Salemi a confederation made up of Salemi, Trapani, Mazara, Monte San Giuliano and by the barons of Castelvetrano and Partanna was formed which undertook the defense, and bore the costs, of the Queen White and Royal House of Aragon. Salemi was, therefore, more fortified and garrisoned during the raids of the Turks.
The trulli, typical limestone dwellings of Alberobello in the southern Italian region of Puglia, are remarkable examples of corbelled dry-stone construction, a prehistoric building technique still in use in this region. These structures, dating from as early as the mid-14th century, characteristically feature pyramidal, domed, or conical roofs built up of corbelled limestone slabs. Although rural trulli can be found all along the Itria Valley, their highest concentration and best preserved examples of this architectural form are in the town of Alberobello, where there are over 1500 structures in the quarters of Rione Monti and Aja Piccola.
The property comprises six land parcels extending over an area of 11 hectares. The land parcels comprise two districts of the city (quarters or Rione Monti with 1,030 trulli; Rione Aia Piccola with 590 trulli) and four specific locations.
Trulli (singular, trullo) are traditional dry stone huts with a corbelled roof.