Southeast of Seville and west of Ronda in the Cadiz Province, the scenic Parque Natural Sierra De Grazalema is know for its rocky mountainous areas, green pastoral river valleys and Mediterranean woodlands. You can choose hikes leading through scenic white-washed villages or try the high altitude trek up El Torreon. Keep in mind though that some of the better hikes are in the reserve area that require guides and permits (some free permits are available from the Centro de Visitantes El Bosque).
Another popular hike is into the lush Garganta Verde, a 100m deep gorge. It is a four hour (5km) roundtrip trek from the trailhead. Just before entering the main ravine, watch for a colony of griffon vultures. To reach the trailhead for Garganta Verde from Grazalema, head west on A372. Turn right heading north on CA9104 towards Zahara de la Sierra for 13.5km. By the way, make sure to try the hike up to the ruined castle in Zahara.
While the Parque Natural Sierra De Grazalema, and inparticular the town of Grazalema, is one of the most lush place in Andalucia due to high rainfall, it can be quite dry in the peak summer months of July and August. The best time to hike is May, June, September and October.
Overall, La Garganta Verde is the 10th most popular hiking trail of all 21 hikes in Spain.