The Red Route in El Torcal is officially closed and you need permits to hike it. There are guided tours from the visitors center.
The Cornisa del Diablo (The devil’s cornice or ledge) refers to the pass on the upper section of the hike and is the main reason this path is now off limits. There have been several accidents over the years and I don’t recommend walking it.
You need to take a lot of care if attempting it. This is the track to follow if you do.
You can walk the red route and avoid the Cornisa completely. However, you need to know where to turn into the mountains and off the path – it’s just past a rock known as the sombrero.