Segesta was founded high upon Mount Barbaro by the Elymian people, one of three Bronze Age cultures that flourished in Sicily before the arrival of overseas powers. Eventually, though, the foreigners came knocking and, after a doomed alliance with Carthage, Segesta attached its fortunes to Athens. The Romans and Arabs also took possession of Segesta, but the city was abandoned completely at some point during the Middle Ages. This desertion allowed Segesta's ruins to survive relatively untouched, shielded from the destructive march of history.
If you're an adult human living in the 21st century, you have at some point in your life suffered a catastrophic computer crash. You've been faced with the choice of whether to try and recover your system, or just start fresh with a clean install. And you've probably learned that, almost always, the best option is to start clean and reinstall from scratch. Restorations rarely work and, even if you're able to cobble your computer back to a semi-functional state, there are usually problems. No, it's best to bite the bullet, lose some work, and start over. For metaphorical proof from history, just look at the Sicilian city of Noto.
Set atop a mountain overlooking Trapani, in Sicily's northwestern corner, the town of Erice has a history rooted in mythology. We spent a few hours getting lost on the uneven stone roads and tiny alleys which curve senselessly about the town, and felt as though we'd stepped back in time. If only the weather had played along.
Palermo is bounded to the north by Monte Pellegrino, a rock jutting into the Mediterranean which Goethe described as "the most beautiful promontory in the world". Near the mountain's summit is the Santuario di Santa Rosalia, one of Palermo's many patron saints. The mountain park and the sanctuary can be easily visited in a few hours, and make a great escape from the noise and traffic of the city.
One of the best birds-eye views of Palermo can be had from the top of the Torre di San Nicolò, near the Ballarò market in the Albergheria. The late-Gothic tower was constructed in the 13th century for defensive purposes, and now belongs to the adjoining San Nicolò church. For a structure built so long ago, the tower is in remarkable condition, and you'd have a hard time finding a better panorama of the medieval city.