Pozo Airón

Pozo Airón is a striking waterfall in the municipality of Pereña de la Ribera, in the province of Salamanca, tucked into a rocky gorge right beside the Duero river. It sits inside the Arribes del Duero Natural Park, in a stretch where the river cuts deep into granite slopes, shaping one of western Spain's most distinctive landscapes.

What exactly is it?

The waterfall is formed by the Arroyo de los Cuernos stream (also known locally as de la Rueda), which drops roughly twenty metres just before joining the Duero. The water slides down a rock channel like a natural chute, and at its base, tucked behind the curtain of falling water, there's a hidden cave. That's what gives Pozo Airón its local nickname of "reversible waterfall": it can be enjoyed from two angles — from the outside, watching the water fall, and from inside the cave, sitting behind the water curtain itself and hearing it rush just overhead.

How do you get there?

The starting point is the village of Pereña de la Ribera, about 90 km from Salamanca. The trail begins near the Santa María church. The first kilometre and a half follows an access track that can partly be driven, after which the route turns into a forest path descending toward the gorge. The full round trip covers about 5.6 km and takes roughly 2 hours 15 minutes. The trail isn't officially waymarked, but the path itself is easy to follow. Watch your footing near the waterfall itself, where rocks get wet and slippery, especially after rain.

What will you see there?

The descent crosses a landscape with a Mediterranean-style microclimate — along the way you'll pass olive groves, hackberry trees, junipers and rockrose shrubs, vegetation more typical of eastern Spain than of inland Castilla y León. The waterfall itself, despite its modest twenty-metre drop, feels much bigger thanks to its setting: a deep rocky cut with the Duero flowing just below. The cave behind the cascade works like a natural amphitheater, letting visitors sit and watch the water fall from behind — a rare vantage point among Spanish waterfalls.

Pozo Airón also carries its own local legend. The name "Airón" is linked to a pre-Roman water and well deity, whose worship is said to date back to the Neolithic. In local folklore, sites like this one were considered gateways to the underworld, guarded by a capricious god of the depths — similar stories surround other "pozos airón" scattered across Spain.

When should you visit?

The flow of the Arroyo de los Cuernos depends directly on rainfall, so the waterfall looks its best after wet spells, typically in autumn, winter and early spring. During the dry summer months the stream can shrink considerably or even run dry for a time. The route is considered easy and family-friendly, but sturdy trekking shoes are worth packing — the final stretch runs over uneven, rocky ground with a fairly steep descent of around 250 metres.

Frequently Asked Questions

Is the trail to Pozo Airón difficult? No — it's an easy, family-friendly 5.6 km round trip, though the last stretch is steeper and rockier, so solid footwear helps.

Where does the trail start? It starts in Pereña de la Ribera, near the Santa María church. The first 1.5 km can be covered by car along the access track.

Why is the waterfall called "reversible"? Because it can be admired from two perspectives — from outside, watching the cascade fall, and from inside a cave hidden right behind the water.

When does Pozo Airón look its best? The best time is after heavy rain, during autumn, winter and early spring, when the Arroyo de los Cuernos carries the most water.