Palermo Cathedral is a historic church located in the heart of Palermo, Sicily, Italy. Built on the site of a former mosque, it reflects a rich blend of architectural styles, including Norman, Gothic, Baroque, and Neoclassical. Construction began in 1185, and the cathedral has undergone numerous renovations over the centuries. It houses the tombs of several Sicilian rulers, including Emperor Frederick II, and is a UNESCO World Heritage Site as part of the "Arab-Norman Palermo" group.