The visit to the Alhambra was the highlight of my Spanish visit. We showed up early in the morning, and spent a good portion of the day touring the Alhambra.
The Alhambra is located on top of a hill (known as La Sabika). Inside are many interesting building and architectural complexes, including the Alcazaba (the fortress/citadel), the Palicio Nazaries (Nasrid Palace), and the Generalife (the Alhambra's gardens).
As I already noted, the first palace on the site of the Alhambra was built in the 11th century. After the Christian conquest the "Catholic Monarchs" (Ferdinand and Isabella) appointed a Muslim to restore the decoration of the Palacio Nazaries. Eventually the Alhambra's mosque was replaced with a church. Carlos I, grandson the of the "Catholic Monarchs" had a wing of the Palacio Nazaries destroyed, to make room for a huge palace, the Palacio de Carlos V (which was Carlos' title as Holy Roman Emperor).
Over the centuries the Alhambra fell into disuse, and by the 18th century, it was purportedly a large "den" for thieves and beggars. During the time of Napoleon, it was a barracks, and purportedly was almost blown up. Then around 1870, as a result of a huge interest in the site by some Romantic writers (including Washing Irving in his book "Tales of the Alhambra") it was declared a "national monument", and the restoration started.