The prior palace of the aristocratic Gravina Cruyllas, Princes of Palagonia, was razed by the 1693 Sicily earthquake. The palace was rebuilt in the 18th-century, rising next to the ruins of the Teatro Romano. Originally the main portal faced via Vittorio Emanuele, but now faces the piazza. The architect is unknown, but has similarities to the work of Francesco Battaglia. The building has undergone many modifications, including addition of a fourth floor after 1924. The house was declared a national monument in 1923, and inaugurated as a museum by 1930.