Valderejo Natural Park is situated in a wide valley surrounded by limestone cliffs. This area marks a transition between the Atlantic and Mediterranean climates, with warm, dry summers and winters with abundant snowfall, providing it with a high level of biodiversity. Species of plants and fauna typical of both weather systems can be found in the Park. The main river in Valderejo is the Purón, which has its source to the north of Lahoz.
Woods constitute more than 58% of the total vegetation. The Scottish pine is the most widespread, followed by the holm oak, beech and there is a small area covered by gall-oaks. Meadows and crops occupy the floor of the valley, surrounding a number of ancient villages. This vast plateau is occupied by a mosaic of pastures and scrubland and in some places there are outcrops of limestone rock.
The variety of ecosystems and the negligible presence of man has favoured the development of a rich and varied fauna: large mammals such as roebuck and wild boar, an interesting community of medium-size carnivores, a large colony of vultures which has become the emblem of the Park and a wide variety of a rock and forest birds.
Valderejo Natural Park has areas of great natural and cultural interest such as the Lahoz/Sobrón anticline, the ravine formed by the river Purón, its numerous forests and its rural population centres; in addition to its superb landscapes that provie a setting for the conservation of this area's traditional farming practices and cultural heritage, forming an interesting mixture of nature and rural life.
The recreational and interpretation centre is located in Lalastra. There, next to the Parketxea or Information Centre, you can find a recreational area with facilities for children and areas where you can picnic. There are also several restaurants and rural guesthouses, ideal for getting your strength back after a visit to the Park, especially if you have explored its networks of paths (9 in all), with lengths of between 3.5 and almost 12 km.