Please answer the following question: The Castello Normanno (Norman Castle) or alternatively the Castello di Aci (Castle of Aci) is a castle located in Aci Castello in the Province of Catania in Sicily. Its precise date of construction is uncertain but it was important to the development of its region during the Middle Ages. During the War of the Sicilian Vespers it was subject to Roger of Lauria. It was besieged more than once and was also briefly controlled by the Spanish. It is currently a museum. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Building