This cathedral, located right outside of Palermo, is clearly a favorite among travelers as well as reviewers. One TripAdvisor user says: "The draw here is the incredible, lavish hand worked mosaics that cover every inch of the ceilings and a good bit of the walls. Entrance into the Cathedral itself is free. What a bargain!" Frommer's says this: "Arabo-Norman art and architecture reached the pinnacle of its beauty in this cathedral, launched in 1174 by William II."

Pay particular attention to the bronze doors, which are covered in dozens of biblical scenes. These were designed by none-other-than Bonanno Pisano, who was responsible for the Leaning Tower of Pisa (although this is now being debated). The cathedral's fold interior envelopes you as you step inside. The mosaics are particularly arresting. And though you'll be charged a small fee to ascend the terraces, we highly recommend it; the bird's eye view of first the church and then the surrounding countryside is not to be missed.

Admission to the Monreale Duomo itself is free, but features like cloisters, treasury and terraces each cost a small fee to explore. From May to September, the cathedral is open daily from 8 a.m. to 6 p.m. The rest of the year, it closes for a midday siesta at 12:30 p.m. to reopen at 3:30 p.m.