Muqarnas

Wiki: "Muqarnas developed around the middle of the 10th century in northeastern Iran and almost simultaneously — but seemingly independently — in central North Africa. Examples can be found in the Alhambra in Granada, Spain, the Abbasid Palace in Baghdad, Iraq, and the mausoleum of Sultan Qaitbay, Cairo, Egypt.[2] Large rectangular roofs in wood with muqarnas-style decoration adorn the 12th century Cappella Palatina in Palermo, Sicily, and other important buildings in Norman Sicily. They are also found in Armenian architecture"