The loop starts and ends in Miraflores de la Sierra. The M-611 climbs straight away towards the Puerto de la Morcuera through pine forest, with La Pedriza in view, and on the other side drops openly towards Rascafría and the Lozoya valley.
From Rascafría the route follows the valley through Pinilla del Valle and Lozoya to Gargantilla del Lozoya, where the M-629 begins, climbing to the Puerto de Canencia through dense woodland before descending towards Canencia and returning to Miraflores along the M-604 near Bustarviejo. It is one of the best-known loops around the Sierra de Guadarrama National Park.
It is about 65 km and just under two hours without stops, with around 180 bends and seven hairpins. Altitude ranges from about 1,020 m to 1,776 m: the whole loop is mountain riding. There are many cyclists, especially at weekends, and livestock up high.