The Cathedral of Palermo exhibits many styles as it owns a long history of additions, alterations and restorations, the last of which occurred in the 18th century.
The main façade on the Western side is flanked by two towers and has a Gothic portal surmounted by a niche with a precious 15th century Madonna. Two lintelled ogival arcades, stepping over the street, connect the façade to the bell tower in the front, annexed to the Archbishops Palace. This has a squared appearance adorned in the upper part by a fine crown of smaller belfries and small arcades.
The right side has outstretching turrets and a wide portico in Gothic-Catalan style with three arcades. The mosaic portraying the Madonna is from the 13th century, while the two monuments on the walls, works of the early 18th century, represents King Charles III of Bourbon and Victor Amadeus II of Sardinia.
The area of the apse is enclosed by the turrets and grandly decorated on the external walls. The interior has a Latin cross plan, with a nave and two aisles divided by pilasters. In the first two chapels of the right aisle are the tomb of emperors and royal figures moved here in the 18th century from their original sites. Here are the remains of Emperor Henry VI, his son Frederick II, as well as those of Peter II of Sicily.
The Sacrament chapel, at the end of the left aisles, is decorated with precious stones and lapislazuli. To the right is the chapel of Saint Rosalia, patron of Palermo.
The Cathedral has a heliometer (solar “observatory”) which works on the principle of pinhole camera and projects an image of the sun onto the floor at solar noon (12:00 in winter, 13:00 in summer). There is a bronze line, la Meridiana on the floor, running precisely N/S. The ends of the line mark the positions as at the summer and winter solstices; signs of the zodiac show the various other dates throughout the year.