Ten minutes up the hill from the apartment, underneath the banana terraces, is the longest lava tube in Europe. Around eighteen kilometres of it have been mapped, which puts Cueva del Viento among the longest in the world — behind only a handful on Hawaii — and it is often described as the most complex, because it runs on several levels rather than as a single passage.
What a lava tube actually is
When a lava flow moves downhill, its surface cools and hardens while the molten rock underneath keeps running. Eventually the supply stops, the liquid drains away, and what is left is a hollow tube through solid rock.
Cueva del Viento formed in flows from Pico Viejo, on Teide’s flank, and the structure inside — the lateral terraces marking old lava levels, the stalactites of solidified rock, the side passages where flows split — is why volcanologists rate it so highly. It is not a cave in the limestone sense. Nothing dissolved to make it. It was cast.
Visiting
Only a 300-metre section is adapted for visitors, and access is by guided tour only. Allow around two hours in total: a briefing, a walk through the surrounding land to the entrance, and the underground section itself.
Helmets and lights are provided. Wear closed shoes with grip and take a layer — the floor is uneven volcanic rock and it is cooler down there than in the sun outside.
Book ahead. English-language slots fill first, and this is one of the few attractions on this coast where turning up hopefully does not work. If your dates are fixed, book before you fly.
Why it is worth doing
Tenerife’s volcanic story is usually experienced from the outside: lava fields at Chinyero, the buried harbour at Garachico, the caldera at Teide. This is the one place you get inside it.
It is also, by a wide margin, the most significant natural site within ten minutes of the apartment — and considerably less visited than it deserves.