The Hoces del Río Riaza Natural Park, located in the northeast of the province of Segovia and very close to the border with Burgos, is a real treasure within the Ribera del Duero Wine Route. This space is articulated around the Riaza River, which runs through the landscape from southeast to northwest, separating three important areas within the territory:

• The first area stretches from the town of Maderuelo to the Linares del Arroyo dam. Here, the river flows serenely, dammed since 1951, in a region that stands out for its gentler relief.
• The second area, between the dam and the stream of El Casuar, covers 5.5 kilometres where the river Riaza has carved an impressive limestone canyon. This canyon, with walls up to 150 metres high and a width varying between 200 and 300 metres, offers a unique geological spectacle.
• Finally, in the third area, the river Riaza leaves the limestone behind when it reaches Montejo de la Vega, opening up an asymmetrical valley with a fertile plain at its bottom, ideal for the development of wildlife and agriculture.

This route through theNatural Park offers a fascinating experience for nature lovers, where each stretch of the river reveals a different facet of this privileged environment.

Today we would like to invite you to travel through the Natural Park to learn more about one of our most precious resources.

1. Park House

In Montejo de la Vega de la Serrezuela, you will find the Casa del Parque. This space has a public service area that serves as an information point to find out about the routes that can be taken inside the Park and the areas of interest that can be found in the surrounding area.

In addition, the House has a small museum of interpretation of the Natural Park in which, through models, photographs and other resources, visitors can better understand the place and its importance during their visit.

2. Live camera

One of the surprises hidden in the Casa del Parque is that, among all the resources we can find in it, we will be able to see, through a camera, a live nest.

This camera is part of the collaboration agreement signed between the Natural Heritage Foundation and the Ribera del Duero Wine Route and allows us to follow the evolution and life inside the nest.

3. More than 150 pairs of griffon vultures

One of the greatest attractions of this Natural Area is, without a doubt, its extraordinary diversity of birds. Among them, the most outstanding is its important colony of griffon vultures, with more than 150 pairs. However, we cannot forget other emblematic species such as the Egyptian vulture, the common kestrel, the rock plane, the red-billed chough and the majestic eagle owl, which take advantage of the cracks and hollows of the steep rocky walls to nest.

This corner of nature is a true paradise for bird and wildlife lovers in general, offering a safe haven and a vibrant environment for a wide variety of species.

4. A 12th century Romanesque church

Within the Natural Park, we can find the hermitage of Casuar, a 12th century Romanesque church, partially in ruins, which was declared an Asset of Cultural Interest in 1997.

It is located about 4 km from Montejo de la Vega de la Serrezuela and is currently on Spain’s Red List of Endangered Heritage.

The name of this church comes from the ancient village of Covasuar, where it was originally located. In 913, the village was donated by Fernán González and his mother to the monastery of San Pedro de Arlanza, marking the beginning of its connection with the church, which would be built in the 11th century. From its foundation, the church came under the administration of the Benedictines as the priory of San Pedro de Arlanza.

5. The origin of the canyon

For almost 7 kilometres, the Riaza has carved a valley of vertiginous vertical walls, sculpted out of Turonian limestone, with a depth of around 150 metres and a maximum width of 200 to 300 metres.

The formation of this gorge is due to a natural process in which the river, over time, has been eroding the land through which it flows, digging deep into the rocks it finds in its path. At first, the river flowed through a layer of hard, resistant rock, but over time, it continued to wear away the terrain until it reached a layer of softer rock, where it finally formed its bed or bed.

In addition, the action of water has created small caves and cavities in the valley walls, a process known as karstification. These cavities have caused the walls of the gorge to change and transform over time, as the water, filtering through the cracks and fractures in the rocks, has weakened and worn away the walls of the gorge, causing them to slowly recede and change shape.

6. Railway viaduct

One of the most outstanding landscapes in the park is the one surrounding the viaduct of the Madrid-Burgos railway line. It is a masterpiece of Spanish engineering that has left an important mark on the history of the railway in Spain. Built in 1968, this imposing concrete bridge spans 242 metres and consists of 8 spans, designed to support a double track.

This bridge is not only a key piece in the railway infrastructure, but it has also become an iconic symbol of this line. Its importance is such that it was even depicted on a lottery ticket, capturing the public imagination and cementing its place in the collective memory.

The construction of this viaduct cost 1,245,398 pesetas, a significant investment at the time that reflects the magnitude and ambition of the project. Today, the viaduct remains a testament to the ingenuity and skill of Spanish engineers, and an integral part of the region’s railway landscape.

7. The Montejo refuge is a pioneering model of conservation in Spain since 1974.

Since its creation, this refuge has become a reference model for scientific research, habitat restoration and citizen participation in environmental protection. Several organisations, such as Patrimonio Natural and WWF, remain committed to protecting this unique environment.

The origin of the Refuge dates back to 1974, when Félix Rodríguez de la Fuente, while preparing the series “Man and the Earth”, visited the Riaza River, in the north-east of Segovia. Realising the alarming decline of vulture populations in the region, Félix proposed, together with the local population, the creation of a refuge to conserve the birds of prey.

In November 1974, ADENA (now WWF) and the Hermandad de Labradores y Ganaderos de Montejo de la Vega de la Serrezuela signed an agreement to create a hunting refuge. This agreement marked the first example of land stewardship in Spain and became a pioneering model of private conservation, later replicated in other regions of the country.

The Raptor Refuge was officially inaugurated on 13 January 1975, and since then, the Riaza gorges have been a point of reference for bird lovers and nature conservationists.

In 2004, the Junta de Castilla y León created the Parque Natural de las Hoces del Río Riaza, which includes the 5,185 hectares of the Montejo de la Vega Raptor Refuge, thus increasing its level of protection against future threats.