Eighteen kilometers of tunnels carved by lava 27,000 years ago, beneath the hills of Icod de los Vinos. Cueva del Viento is the 5th longest volcanic tube in the world — and one of the best preserved. The guided tour (2h, 10 people maximum) descends into a network of galleries where the temperature remains constant at 19°C, where fossils of giant endemic lizards are embedded in the rock, and where lava formations take on impossible shapes.
The insider tip: Book as soon as the calendar opens, three months in advance — slots disappear within days. Closed-toe shoes mandatory (slippery terrain). Light jacket recommended despite the constant 19°C.
When lava flows rapidly from a volcano, the outer surface cools and hardens within hours — forming a crust. Beneath this crust, the lava continues to flow, then eventually drains away. A tunnel remains: this is the volcanic tube. In the case of Cueva del Viento, the eruption that formed it lasted several centuries, feeding a river of lava from Teide to the sea.
The result: galleries that can reach 15 meters high and 20 meters wide, with walls covered in formations called lavacicles (lava stalactites), shelves, and lava balls. Some resemble abstract sculptures, others giant intestines — it's fascinating and slightly unsettling.
The cave's total isolation allowed the evolution of species unique to the world. Fossils of Gallotia goliath, a giant endemic lizard of Tenerife now extinct, were found in Cueva del Viento — the best preserved in the Canaries. Spiders and insects adapted to total darkness still live in the deepest galleries.
The Interpretation Centre on the surface explains this underground biodiversity with scale models and specimens — worth seeing before descending to better appreciate what you'll observe.