Originally known as the Castello del Buon Aere (Castle of Good Air), the enormous castle that soars above Castelbuono's golden patchwork of houses gave the town its name and is its most distinctive landmark. Built by Francesco I Ventimiglia in 1316, it features displays on local archaeology and Castelbuono's history.
Popular legend has it that the castle is haunted by the 14th-century Queen Constance Chiaramonte, who is said to run along the corridors, regular as clockwork, on the first Tuesday of the month. At the heart of the fortress is the Cappella di Sant'Anna (Chapel of St Anne), which dates from 1683 and is decorated with marvellous stuccowork from the school of renowned Sicilian sculptor Giacomo Serpotta. It houses the supposed skull of the saint in a silver urn.