The interior has nothing to do with the French or Spanish Romanesque. At the time, Italy had a very different architecture and Romanesque ornamentation than we're used to. In Italy, there was much more brightness, the buildings were taller and the presence of windows was important, which are a lot of factors that our Romanesque lacked until the Gothic style came along. But the most surprising thing about the interior is the black and white marble, which is very typical in Italy, as well as the wooden gilded coffered ceiling from the 17th century. Don't miss the Pantocrator in the apse, from the 16th century, and the pulpit, a masterpiece of Giovanni Pisano, from the early 14th century. The huge granite Corinthian columns between nave and apse are of the mosque of Palermo, spoils from the battle of "Cala" in 1063. There is also a huge apse mosaic of Christ by Cimabue from 1302, which survived the fire of 1595.