Two churches in Palermo. Palatine Chapel has 6 tickets and tours to book; Palermo Cathedral has 4 tickets and tours to book. The table and the two notes below put them side by side; the full pages have what to see, the ticket and the timing for each.
The chapel is inside the Norman Palace, which is also the Sicilian regional parliament, so the ticket covers the palace and its royal apartments as well; prices differ on days when the assembly sits and parts are closed. Buying online with a time slot is worth it in summer, when the queue in the courtyard is long and shadeless. Guided tours cost two to three times the entry and are useful because the mosaics carry Greek, Latin and Arabic inscriptions that spell out exactly what the building is arguing.
The church is free to enter; the paid parts are sold as a combined ticket and are worth the small sum. They are the royal tombs, where Frederick II and Roger II lie in porphyry sarcophagi; the treasury, with the jewelled crown of Constance of Aragon taken from her tomb; the crypt, with Roman and medieval sarcophagi reused by archbishops; and the roof walk, which climbs to the terraces for a view over the Cassaro and down onto the domes. The roof is the one to prioritise.
