Circular hike in the Sierra de Guadarrama June 2016

A really nice long-distance hike in the Sierra de Guadarrama, easily accessible from Madrid. The route follows the main ridges of the Guadarrama range. It links a number of trails and paths, with one section without path (on the Collado de Flecha), and several short sections on roads. A good variation would be to include the summit of Penalara, which I missed as a storm was forecast.