Separating the barrancos are the high mountain ridges often called lomos. The roads tend to follow the valley floors, or follow the coastline, although there are some roads over the mountainsides. In recent years, the quality of some of the less accessible roads has been improved with the help of EU grants. That still leaves large areas of undeveloped mountainside for the serious walker. Each barranco has its own particular types of walking opportunity.
Various books are available describing holiday activity, including walking.
Amongst these is Landscapes of Gran Canaria by Noel Rochford. Some care needs to be taken about using mountain routes which he suggests. When we met him in San Pedro some 4 hours later, his comment was that his walk had been extremely frightening, with a very difficult descent. The warnings and advice given by the author of this book should be taken very seriously. He generally recommends mountain boots, rain gear, warm clothing, sunhat and an ample supply of water for all his walks.