When we went to see the Alahambra, it was over a 100 degrees. Tickets for the morning sold out a week ago, so we went in the heat of the afternoon. It is expensive. It is crowded. You get there an hour early to wait in a series of lines. The audioguide is by a guy pretending to be Washington Irving. He said the words delicious and luscious a lot. Was it worth it?

Totally.

The Alahambra is awesome. Any pictures you see will not do it justice. 

It was the center of the caliphate for Grenada province, which was the last Arab bastion to fall to the Reconquista.  It is enormous and situated on a hill, which made it a key part of the military defenses of the city.  It served administrative, military, and judicial functions as well as being home to the Caliph of Granada and those who served him.