The gorge was formed by the erosive action of the Sella River cutting through the limestone massifs of the Picos de Europa.
The passage is legally classified as part of the Picos de Europa National Park's area of influence.
The narrowest sections of the canyon were historically known as 'foces,' which served as natural defensive bottlenecks.
The Sella River, which flows through the base of the gorge, is famous for the annual International Sella River Descent downstream.
The N-625 road through the gorge is considered one of the most winding and technically challenging mountain routes in Northern Spain.
Desfiladero de los Beyos is a dramatic limestone gorge carved by the Sella River, serving as one of the primary entry points to the Picos de Europa National Park. The canyon extends approximately 12 kilometers along the N-625 road, connecting the Asturian town of Cangas de Onís to the high mountain passes of León. Vertical cliffs rise hundreds of meters above the riverbed, creating a narrow, winding corridor that has been a strategic mountain passage for centuries. The gorge is recognized as one of the most impressive examples of erosion in the Cantabrian Mountains. The road hugging the cliffside features numerous tunnels and sharp turns, restricting the passage of large vehicles. Vegetation within the ravine includes dense forests of holm oak and beech, which cling to the sheer rock faces. The gorge marks the boundary between the provinces of Asturias and León at the Pontón Pass.
Any of the designated gravel observation lay-bys located at the wider bends of the N-625.
Drive slowly and prioritize staying within your lane, as the road is narrow with limited visibility around curves.
Check local weather reports for fog or heavy rain, as these conditions significantly reduce visibility and traction on the cliffside road.
Use designated turn-outs or parking bays to pull over; do not stop on the road shoulders as they are often non-existent.
Attempting to pass other vehicles on the narrow curves and stopping in the middle of the road for photographs.
The route may be restricted or closed temporarily during extreme snowfall in winter; exercise caution after heavy rainfall due to potential rockfall.
