Discovering the Largest 'Super Cave' in the Southern Iberian Peninsula in the Sierra de las Nieves

Beneath the Spanish Fir trees of the Sierra de las Nieves, near Tolox, lies a labyrinth of underground caves with kilometers of passages and ... several hundred meters deep. They are called 'supercaves', a term that reflects the uniqueness of these galleries with a dimension unknown until now. However, speleologists are beginning to decipher this complex underground world bit by bit. Members of the Subterranean Explorations Group of the Málaga Excursionist Society have just confirmed the connection between two large pits that were previously known independently. The missing link that leads to the largest 'supercave' in the south of the Iberian Peninsula.

The new Nevero-Aire Complex spans over 26 kilometers and has a vertical drop of 955 meters. It is six kilometers longer than what was considered the largest cave in Andalusia until now, the Sima de la Luz. And this is just the beginning. Experts know, after years of studies, that this last pit also connects at some point – not yet detected – with the previous ones, which would yield a route of almost 50 kilometers under the ground. "It's very beastly, something very exceptional. We are currently opening Pandora's box," says Rogelio Ferrer, one of those few professionals capable of delving into the bowels of the Earth. He spent five days inside it last June.

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Journey to the interior of Málaga's supercaves

We are talking about true underground cathedrals with large vertical shafts hundreds of meters deep, immense chambers up to 30,000 cubic meters in volume (equivalent to four hot air balloons), and long galleries. All this in a small karst system, like the Sierra de las Nieves, compared to the Picos de Europa or the Pyrenees. And this is partly why it amazes experts, that such huge underground systems exist in this very specific area, only seen so far in the north.

But there's more. What the Sierra de las Nieves hides is a true "geological gem" that is being investigated by scientists, because its formation challenges paradigms that seemed firm. Normally, rainwater that seeps into the ground opens fractures in the rock until it reaches a water table. But these 'supercaves' are not born this way. There are very vertical pits with other horizontal networks, they have found galleries several hundred meters below the surface of the water table and flooded caves. This indicates, as geologist Juan José Durán once explained, that there are other hypogenic mechanisms for these cavities to be created, such as waters coming from inside the massif with different chemical elements and temperatures that generate hyperkarstification processes. Something "absolutely atypical".

Years of Work

Speleologists and geologists have been working hand in hand for decades, underground and on the surface, to decode the system of tunnels, pits, and galleries under the Sierra de las Nieves. They knew that some galleries of Nevero and Aire were just about 100 meters apart, they had to coincide somewhere.

It has large vertical pits, immense chambers, and long galleries that extend 26 kilometers and descend to 955 meters

"Like a surgeon," they have delimited the area after a series of high-quality topographies and numerous team assessments. It's not easy, the expeditions have descended to depths of 500 and 600 meters, spending several days without seeing sunlight. Last summer they decided where to attack within that intricate labyrinth. And they were not wrong. On Saturday, September 26, two members of the Subterranean Explorations Group of the Málaga Excursionist Society physically confirmed that this connection between both pits was real in the subsurface of the Natural Park. A milestone for the speleology of the province that places Málaga in the focus of subsurface science.