From here and with some patience and luck we can use the proximity of a scavenger feeder, enjoy the majestic flight of the Griffon Vulture, the most numerous of our great birds of prey, which will delight us with passes a few meters from the crown of the pines. that surround us, it is also possible to contemplate from here other species of raptors such as buzzards and booted eagles.

From here we will continue along the same road until we reach Empalme del Valle (connection point with the main route if the start is from the town of Arroyo Frío), and we will take the crossroads to the right, in the direction of Vadillo-Castril. In this old logging town located on the bank of the Guadalquivir river we can make a second stop, in which, either walking along the banks of the river through the same town or investing a little more time in the realization of a circular route on foot, Also of ornithological interest for the Cerrada del Utrero, we can see a great variety of species of birds typical of the banks such as the Aquatic Blackbird, a good indicator of the quality of this water, the Gray Wagtail in its wandering through the stones that appear from the surface, Bastard Nightingales and in spring the colorful Oropendola among others.

Continuing and after passing the Iron Bridge, located next to the Cerrada de Utrero path, we will arrive at a fork that we will take to the left to go up towards Las Navas. We will leave behind the Lanchales de Linarejos, a beautiful karst area where the agile mountain goat can be observed with some patience and with it and in silence, looking at the trunks of the trees that surround us we can see various species of small forest birds size but great beauty such as Nuthatch, Common Chickadee, Chickadee, Mythos, etc. We continue to the Los Collados forest house where the dirt forest track begins that, through the Cuesta del Bazar, will take us to Nava del Espino.

A little higher up we find, to our right, a first viewpoint that overlooks Los Poyos de la Mesa, where it is common to see the flight of Vultures and hopefully Golden Eagles, Booted Eagles and Short-toed Eagles, the latter in spring. and summer when it is in our mountains after its wintering in Africa

We will continue our journey ascending between beautiful resin pine forests, holm oaks and some old gall oaks, which are associated with an undergrowth made up of rosemary, marjoram, cornicabra and rockrose ... As we ascend the Cuesta del Bazar, the resin pines give way to the majestic black pines. We are in the Oromediterranean floor, where centenary feet of gall oaks, hawthorn, arlos (barberry) or uvilleros spikes, shepherd's cushions are associated with this slender pine ...

We have reached the beginning of the Nava del Espino, a beautiful plateau of lush laricio forests and high mountain pastures. Surrounded by slender peaks such as the Cabeza del Tejo, the Pedro Cerrillo hill ... where it is common to see the fast fallow deer grazing or resting under the shade of a pine tree.

We will continue along the forest track, leaving behind the recreational area of ??the Fuente de la Garganta to reach the Esperilla where we find the second viewpoint dedicated to Félix Rodríguez de la Fuente. This viewpoint gives views over the "Nava de San Pedro" and the "Torcales del Lobo". We must not miss the opportunity to invest some time in this nava to scrutinize this wonderful extension with binoculars to try to discover some Great Spotted Woodpecker, Woodpecker or Crow hidden among the undergrowth or the network of branches of the reforestation poplar trees found here. . It is not uncommon if we look at the sky to discover the silhouette of birds such as the Golden Eagle, the Peregrine Falcon, Griffon Vultures, Ravens or some of the individuals of Bearded Vulture released within the reintroduction project of the species. At present and next to the old Hunting Park of Nava de San Pedro is the Center for Breeding in Captivity of the Quebrantahuesos. An ambitious project that is bearing fruit, as this endangered species has once again flown through these mountains.

We will continue our route and once we have passed the trench, we will see the Vado de las Carretas from where on days with good visibility we will be able to look to the Sierra Nevada National Park. A little further up and next to the old farmhouses of Poyo Manquillo we will find a small path to our left that takes us to the third viewpoint, overlooking a beautiful holm oak grove on limestone slabs, as well as the impressive cliffs of Los Torcales del Lobo and more. distant Cerro de las Cabañas, Puerto Pinillo, Torcal de Linares ...

We will return to our vehicle to, after about two kilometers, find the fourth viewpoint in the place known as the Estrecho de los Perales, beautiful and rare geological formations through which the crystalline waters of the Valdetrillos stream pass. In this place it is easy to observe how the agile mouflon, the mountain males and even the majestic flight of the Golden Eagle, the Griffon Vulture or the Booted Eagle climb vertical walls, but also flocks of strange birds with twisted beaks that are incredibly adapted to feed on the pine forests, the Crossbills, which use this strange morphology in their beaks to extract the pine nuts from the pineapples. Nor should we forget to mention the possibility of observing a small bird, the Serrano Greenfinch.

We will continue the forest track to leave behind the old forest house of "Fuente Acero" and, one km. Further up, you will reach beautiful and impressive limestone cliffs, among which the peaks of Loma del Caballo de Acero, Alto de la Cabrilla and Navalasno stand out, the last places where the bearded vulture nested before its disappearance between 1986 - 87.

We will continue along the forest track and leaving behind the Collado de Fuente Bermejo, we arrive at Collado de la Zarca, where we find on our left an impressive and centenary foot of black pine with more than 300 years. From here you can see beautiful panoramic views of the Barranco del Guadalentín, and the great limestone formations of the Natural Park, such as the aforementioned Navalasno, Poyos de la Carilarga, La Cabrilla ... At the end of the route we arrive at the place called Ramblaseca, Puerta from the renowned Campos de Hernán Perea, a plateau with sparse vegetation due to the harshness of the environmental conditions and especially to the livestock pressure exerted. In these moors it is possible to see countless small birds that take advantage of the livestock troughs to supply themselves with water and among which we can highlight Finches, Crossbills, Thrush, Red Rock and White-capped Blackbirds (the latter two more frequent in winter) as well as some Goshawk and Sparrowhawk waiting to catch some of the birds that, by quenching their thirst, lower their guard.

Now we only have to return by the same itinerary, until the crossing of the Puente de las Herrerías where we will have the option to choose whether to return by the same path of the first leg, or by the one that runs to the Source of the Guadalquivir and from here to the Chorro where we will be able to enjoy a vulture located in some vertical cliffs of imposing beauty from where we can contemplate Griffon Vultures, Red-billed Chough, Rock Planes and in the breeding season Egyptian Vultures and Royal Swifts. Note that this alternative would considerably increase the time and distance of the journey, so it is recommended to do it on another day.