Detail from the Alhambra, Granada, Spain

It is hard to imagine the artistic effort that went into the construction of the Alhambra in Granada, Spain. Here is a short summary of the work:

The decoration consists for the upper part of the walls, as a rule, of Arabic inscriptions—mostly poems by Ibn Zamrak and others praising the palace—that are manipulated into geometrical patterns with vegetal background set onto an arabesque setting ("Ataurique"). Much of this ornament is carved stucco (plaster) rather than stone. Tile mosaics ("alicatado"), with complicated mathematical patterns ("tracería", most precisely "lacería"), are largely used as panelling for the lower part. Similar designs are displayed on wooden ceilings (Alfarje).[4] Muqarnas are the main elements for vaulting with stucco, and some of the most accomplished dome examples of this kind are in the Court of the Lions halls. The palace complex is designed in the Nasrid style, the last blooming of Islamic Art in the Iberian Peninsula, that had a great influence on the Maghreb to the present day, and on contemporary Mudejar Art, which is characteristic of western elements reinterpreted into Islamic forms and widely popular during the Reconquista in Spain.

See Wikipedia: Alhambra.