The castrense area is where the soldiers used to live. It probably housed an elite group of high quality soldiers capable of defending the Sultan at any moment. Only the outline of the walls remains. It looks like a giant maze. Little has been written about the barrio castrense and one has to use a lot of imagination to visualise what it one looked like when it housed the soldiers. Many people don't realise that the Alhambra was once a bustling town of around 5000 inhabitants. There are a couple of places where you can look down to the dungeons below. A lot of people have thrown coins down there. Someone will have to go down there periodically to sweep them up. There must be a mixture a small coins from almost every country in the world.
The Castrense name comes from the Latin "castrum" which means camp, its plural "castra orum " means "fortified army camp". .