Geoparque Unesco

10 Añisclo Anticline formation (Road from Laspuña to El Pueyo de Araguás)

A world in ruins (Ctra. Laspuña – El Pueyo de Araguás)

Localización : Área de descanso en la carretera que une Laspuña con El Pueyo de Araguás.

Coordenadas. 267523 4707110 31 N

Textos Esperanza Fernández (Geopage)

Even as a mountain starts to be formed, it simultaneously begins to be destroyed by external geological agents such as water, ice, wind, gravity and living creatures, which commence their role in shaping the landscape. In this way, unique rocky structures are formed, often of overwhelming beauty. When we admire these landscapes, we are not usually aware of the fact that what we are looking at are the ruins of something much bigger: a huge geological structure which is being destroyed and which over time will eventually disappear.

Gran estructura en forma de pliegue anticlinal de Añisclo. Se observa cómo su núcleo está siendo erosionado y destruido por la acción de río Bellós y de otros agentes geológicos externos. Fotografía: Ander Gómez..

Detalle del anticlinal de Añisclo tal y como se observa actualmente, tras millones de años de destrucción incesante. Fotografía: Ander Gómez..

From this viewpoint, we can see the large anticlinal fold of Añisclo. Its history can be told in three episodes:

Episode 1

Between approximately 86 and 56 million years ago. Successive horizontal layers of sediment were deposited on the seafloor. These sediments were buried under the Earth's surface, where they were transformed into stratified rocks.

Episode 2

About 45 million years ago. Due to the collision between the Iberian Peninsula and Europe, the stratified rocks folded into a dome shape (anticlinal fold) and fractured (fault).

Episode 3

External geological agents have acted on the rocks since their formation, first lifting them from below the surface and then destroying the structure. In the last million years, the Bellos River has taken advantage of the weakness produced by the fault, and even today continues to gouge out the middle of the fold.

Did you know that...?


Geologically speaking, the Pyrenees mountain range is young. It began to be formed in the late Mesozoic Era, about 65 million years ago, as a result of the collision between the Iberian Peninsula and southern Europe. The persistence of occasional earthquakes centred on the Pyrenees is a sign that these mountains are still being formed, although present geological actions are predominantly destructive.

Recomentations in your visit to Sobrarbe-Pirineos Geopark

  • Safe visits, unforgettable experiences. There are companies who collaborate with the Geopark where you can hire specialized guides to make your tour a unique and safe experience.
  • Respect the geological outcrops. Do not break off samples of rock, mineral or fossils.

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