
Given the following passage

"Increasing military and cultural contacts with the Muslim world, including the Norman conquest of Islamic Sicily in 1090, the Crusades, beginning 1096, and the Islamic presence in Spain, may have influenced Medieval Europe's adoption of the pointed arch, although this hypothesis remains controversial. Certainly, in those parts of the Western Mediterranean subject to Islamic control or influence, rich regional variants arose, fusing Romanesque and later Gothic traditions with Islamic decorative forms, as seen, for example, in Monreale and Cefalù Cathedrals, the Alcázar of Seville, and Teruel Cathedral.",

answer the following question. Note that the answer is present within the text.

Question: What area of interest is being explained in the article? 

decorative forms
