“Sicily is not Italy,” reads stenciled graffiti around Palermo, a sign that some in the Sicilian capital view the city as both a physical and cultural outlier from the mainland.

Influenced by Greek, Roman, Byzantine, Arab, Norman and Spanish conquerors, the port city has long been known for its distinctive dialect, original street food, medieval churches, faded Baroque buildings and — less happily — a historical association with the Mafia.