The church of San Giovanni degli Eremiti dates back to 581 as a Benedictine monastery. Converted into a mosque during the Islamic conquest of Sicily, it was returned to the Benedictine order around 1136 with the taking of the island by the Normans.
Palermo Cathedral was founded in 1185 on an ancient Roman basilica turned into a mosque in the 9th century. The building combines many different styles, ranging from Norman to Moorish and Baroque. It is a UNESCO World Heritage Site since 2015.
The Martorana or Santa Maria dell'Ammiraglio was built in the 12th century in the Arab-Norman style. Despite numerous restructuring and renovation, the Martorana is known for having incredibly well preserved 12th-century Byzantine mosaics. It is a UNESCO World Cultural Heritage site since 2015.