The Duratón canyon is a valley nestled between the plateau of the Segovian páramo with walls that reach one hundred meters in several areas and an average width of fifty meters. The road draws the river line of the canyon, it is winding and undulating between imposing limestone and dolomite walls that have suffered a forceful wear of karstic dissolution for millions of years. At first the water filtered into the earth, forming an underground water course below the current course and due to erosion the roof and the side walls collapsed and the current bed emerged, although much narrower. Later periglacial modeling continued to affect the cuts in the gorges and increased the width of the gorge until the gorges became what they are today. The bottom of the river valley is an alluvial plain of gravel, sand, silt and clay where forest species grow that fill the interior of the gorge with life and color up to the meanders of the Burgomillodo reservoir, in the final stretch of the river within of the space of the natural park. In the central part of the gorges is the mouth of the Valdemuelas stream, a narrow gorge that descends from Villar de Sobrepeña, the area where the largest community of griffon vultures and birds of prey in the natural park is concentrated.
The path is a constant gallery of poplars, poplars, alders, ash trees, willows, elms and other forest species associated with water courses. In some meanders the plain is more extensive and there are old plantations of walnut, chestnut, plum and wild hazelnut trees, the autumn festival of color is guaranteed. More than five hundred pairs of griffon vultures nest on the walls of the gorges, there are also Egyptian vultures, golden eagles and peregrine falcons.