This vast nature park is named for its handsome, and beautifully kept cork tree grove, one of the world's largest. It is also home to wild olive trees, gall oak and holm oak. The far south of the region is crossed by very humid, narrow valleys called canutos, which provide an ideal habitat for sub-tropical forests of great ecological value, as well as animals such as the otter, Egyptian mongoose, imperial and royal eagle and royal owl. The area is rich in game, including boar, roebuck and deer.

These low hills, which are the prolongation of the Sierra de Grazalema as it descends towards the sea, are home to one of Andalucia's largest wooded areas. Cádiz province, in its mountainous eastern part, shares this natural park with Málaga province to the west. Basically a continuation of the sierra de Grazalema, it is one of the most important forest regions of Andalucia, and the best example of what the primeval Iberian forests may have been like. It contains groves of cork oak and gall oak, and the southern sector contains a botanical jewel, the rare fern Psilotum nudum, the only other examples of which occur in the southern hemisphere.

These woods are a paradise for birds. In them live some of Europe's greatest concentrations of lion buzzards, eagle owls and various eagles. Roe deer have been successfully introduced and are thriving. The oaks stretch to the strait of Gibraltar and to Tarifa and Algeciras.