One of the best features of the Alhambra are its intricately carved walls and windows, which retain their Arabic roots in the Moorish period of Spain. The Nasrids (1230s to late 1400s) employed design elements prevalent in Muslim architecture, from the arabesques (vine-like carvings) and calligraphy carvings, to the elaborately sculpted horseshoe door arches and stalactite ceilings. The entire effect can be pretty overwhelming at first, but it grows on you.
It was a pretty bright day when I visited the Alhambra, so this was a very contrasty image. A vignette was manually added to the image in post-processing to bring out the features. Arabian nights anybody?