The Rocca di Cefalú, a rock mass 268 mt. of elevation, represents one of the Ceflaú icons. The city was build at its slopes and from it were taken the materials needed for city construction. Probably the city ancient name, Kephaloidion which comes from the greek Kefalis or rather "head", came from the Rock profile. On its summit can still be found the Mediterranean "macchia" and the peregrine falcon.

On the Rocca is located the Temple of Diana, a megalithic construction of the 9th century b.c., built to celebrate the local water worship. In the Byzantine era a church was build there and it took also a defensive function due to its strategic position. On top of the Rock there are the Byzantine fortifications with crenellated medieval walls. Lastly. on top are located the ruins of Cefalú Castle, build in 14 century. Only the structure stones remain but they allow to track the building planimetry which included two towers and an area divided in 12 sections.