The charming town of Cefalù lies beneath a great rock, the Rocca. The Ancient Greeks felt that this rock closely resembled a human head (κεφαλή) and therefore called the town Kephaloidion. In the Byzantine era Kephaloidion was a prosperous town that had its own bishop. This era started in the year 535 with the recapture of Sicily from the Ostrogoths by the famous general Belisarius and was ushered towards the exit in 827, when the Muslim Aghlabids from North Africa – who had been invited by the Byzantine commander Euphemius – attacked the island. The Muslims subsequently conquered most of Sicily between 827 and 878 and established an emirate on the island. Kephaloidion fell into their hands in 858. The town was but a shadow of its former glory when it was captured in 1063 by the Norman conqueror Roger I, who campaigned on Sicily together with his older brother Robert Guiscard and with full support from the Pope in Rome. Roger I would largely destroy what was left of Kephaloidion, but the town was rebuilt by his son Roger II, who in 1130 became the first King of Sicily. It is to Roger II that we owe the marvellous cathedral of Cefalù, which is UNESCO world heritage.
Climbing the Rocca offers a lot of insight into the history of Cefalù, as one can find quite a few remnants of old buildings on the rock. The rock is part of a park that can be entered after buying a ticket. After he or she has paid, the visitor is given a number, which has to be shown to the park staff after the climb, so that they know that everyone has come down safely again.
The first vantage point offers a beautiful view of the more modern part of Cefalù, with its tourist hotels and narrow sand beaches (see the image above). Much more interesting for history enthusiasts are the archaeological remains of a residential area a bit higher up the rock. This area must have been built between the sixth and eighth century, when the inhabitants of the lower parts of the town were attacked from North Africa, first by the Vandals (whose kingdom was destroyed in 534 by the aforementioned Belisarius) and then by the Muslims. The lower parts of the town continued to exist, but the part on the rock was completely self-sufficient, which is demonstrated by the presence of cisterns, ovens and warehouses. There was also a church dedicated to Saint Anne. The buildings of which we can nowadays see the remnants date from the eleventh to sixteenth centuries, but practically all of them were built over older buildings.
If you want, you can walk all the way to the top of the rock and visit the ruins of the Norman castle. I myself preferred going to the west side of the Rocca, where one has a splendid view of the old part of the town and of the beautiful cathedral of King Roger II. A little bit further to the east are the remains of the so-called “temple of Diana”. This is a megalithic building, made of blocks of limestone that have been stacked without using cement. The building is rather tentatively dated to the ninth or eighth century BCE and was very likely used for religious purposes (according to an information panel the only door of the structure is oriented towards the equinox, the setting sun and the planet Venus). The “temple of Diana” is often compared to other megalithic constructions in the Mediterranean. The ”temple” was in any case already present when Phoenician and Greek colonists arrived on the island. Greeks and Romans subsequently altered the building, which probably explains its Roman name. In the Middle Ages the sanctuary was converted into a church dedicated to the obscure Saint Venera, a female saint who was said to have preached on Sicily in the second century.
 John Julius Norwich, The Kingdom in the Sun, p. 12.