Muqarnas is the transcription of an Arabic word that is usually translated by " stalacites". These are three-dimensional structures, made using concave elements, which may be numerous, and which are often ornamental than structural.
Muqarnas are used in corner squinches or pendentives in domed rooms, or to decorate cornices, corbel arches, capitals. They are sometimes used as simple friezes, but are always placed high enough so as not to tire the viewer.
Their most spectacular applications are on ceilings and domes, where it is easy to see them as stalactites. Muqarnas first appeared discreetly of the 10th century , and new forms evolved quickly and spread with surprising speed as far as Tukestan and Andalusia, just like the flat geometric motifs, of which muqarnas are, in some way, the three-dimensional constitution. Muqarnas have no equivalent in any other civilization, and by their profond originality and their quasi-systematic application, they are one of the major elements of fine Moroccan architecture, Moorish architecture, and Islamic architecture.