I went last year to Grazalema Natural Park.
It is a wonderful place. This park was declared a Biosphere Reserve in 1977.
These mountains are in the province of Cádiz, near the city of Ronda.
They say it is the rainiest place in Spain, and here is the only place in the world where you can find forests of pinsapos (abies pinsapus). Well, you can also find them in the Sierra de las Nieves, near Grazalema.
Pinsapos are a kind of fir that only grow in Andalucia, in nothern Morocco there is a very similar variety of the same tree.
I think you have to make a reservation a long time before you visit the park, and in summer is not allowed to enter due to risk of fire.
http://www.grazalema.es/ http://www.cadiz-es.com/Grazalema/ http://en.wikipedia.org/wiki/Sierra_de_Grazalema_Natural_Park