The Alhambra of Granada is a true work of art and reminiscent of a time in history few people know about - when Arabs ruled much of Europe. I have been there twice, and while my first visit in 1996 was just a quick day trip from the Costa del Sol, in 2013 I made sure to invest some time and effort to really see it all. The main palace is a breathtakingly beautiful place, and the Generalife Gardens and the Alcazaba Fortress are very impressive as well. You can easily spend a whole day in the complex, but after a while it will get exhausting. As mentioned elsewhere, advance reservations are highly recommended. The rest of Granada is quite interesting as well, including the Albayzín quarter with the Arab baths and the stunning San Nicol's viewpoint overlooking the Alhambra, and the Sacromonte district with its cave dwellings. The city centre features a very large Renaissance cathedral and the adjoining chapel containing the tombs of King Ferdinand of Aragon and Queen Isabel of Castile, whose marriage in 1469 paved the way for the ouster of the Arabs from Europe, a united Spain, and the conquest of the New World.