 While Fatimid architecture followed traditional plans and aesthetics , it differed in architectural details such as the massive portals of some mosques and their elaborate façades . Scholars such as <unk> Kuban describe Fatimid architecture as " inventive more in decoration than in broad architectural concept " , although he acknowledges that the Fatimids contributed to a distinct style of mosque . The Fatimids introduced or developed the usage of the four @-@ <unk> keel arch and the muqarnas squinch , a feature connecting the square to the dome . The muqarnas squinch was a complex innovation . In it a niche was placed between two niche segments , over which there was another niche . It is possible that this design had Iranian inspiration . A similar system was applied to window building . According to De Lacy O 'Leary , the horse @-@ shoe arch was developed in Egypt under Fatimid rule and is not of Persian origin as is commonly thought . 
