At a time when climate change is causing glaciers to collapse across the globe—triggering catastrophes and terrifying floods—Mount Etna, too, is losing one of its “secret” glaciers. Yet, this loss is not due to rising global temperatures; rather, it is the result of recent intense eruptive activity that also triggered an earthquake. The quake caused the entrance section of Grotta Tremila (Grotto 3000) to collapse, sealing off access to the glacier forever. So, it is the end… but only for the human eye.The real fact is, Grotta Tremila is far from being lost. Quite the opposite!
A recent discovery
As we previously reported (in an article dedicated to the Teri brothers ), Grotta Tremila is a very recent discovery, dating back to 2022. It was during the Covid lockdowns that explorers Dario and Paolo Teri—while traversing areas of Etna within their own municipality—found two mysterious cavities, both filled with ice. Until then, it was believed that only one glacier-cave existed within the volcano’s depths (specifically, Grotta del Gelo). However, the explorations conducted by the Teri brothers between 2020 and 2022 identified Grotta Polare and—most recently—Grotta Tremila, located at an altitude of 3,000 meters. It is quite possible that Etna conceals many other similar caves that function as true glaciers—albeit underground ones, shielded from external heat.
Grotta Tremila and its wonders
Grotta Tremila is one of the most interesting natural cavities in Etna Park , home to Sicily’s great volcano. It is a lava cave that, thanks to the unique high-mountain climate, can retain snow and ice for extended periods. For this reason, it is sometimes associated with Etna’s ancient “glaciers.”
The cave formed as a result of the volcanic eruptions that have shaped the volcano’s history. When lava flows down Etna’s slopes, the outer layer can cool and solidify while the lava continues to flow within. Once the molten material drains away, an empty tunnel may remain—creating a lava cave. Grotta Tremila is particularly notable for the presence of ice and snow, phenomena fostered by its high altitude and low temperatures. Ice can become trapped inside the cavity, sheltered from direct sunlight and fluctuations in external temperatures. These conditions offer an opportunity to study the interplay between the volcano, the climate, and the natural environment.
Grotta Tremila thus stands as a fascinating example of the extraordinary diversity of environments found on Etna, where volcanic activity and extreme climatic conditions converge.
Etna: ice and lava
Mount Etna features numerous lava tubes, some of which possess characteristics that allow for the preservation of ice. These environments are highly delicate and require careful exploration to avoid damaging natural formations. Grotta del Gelo and Grotta Polare are the most famous examples, alongside Grotta Tremila.
Grotta del Gelo is particularly renowned because it retains ice throughout the year. This phenomenon is due to low temperatures and the cave’s unique shape, which promotes the accumulation and retention of cold air. Consequently, it represents a natural environment of great scientific and geographical interest. Grotta Polare also bears witness to Etna’s intense volcanic activity; its walls clearly display traces of lava flow, offering insight into the processes that have shaped the volcano over time.
These caves constitute an important natural heritage site as well as a valuable water reserve, fed by the slow melting of ice and filtration through the rock. Visiting these fascinating underground glaciers on Etna reveals a hidden, evocative side of the volcano.
Can Etna’s glaciers be explored?
Access to Grotta Tremila is now closed. The earthquake in August 2026 caused the entrance to collapse, sealing off the tunnel—perhaps forever. Paradoxically, this is beneficial for the glacier, as it remains free from contamination by tourists or sightseers.
In reality, these glacier-caves should not be open to tourism, given their status as precious reserves of pure water. Nevertheless, many guides still organize excursions to visit them. The routes leading to the ice caves are not easy, so very few “brave souls” venture along these strenuous paths.
Exploring the Grotta del Gelo (Ice Cave), for instance, is a grueling undertaking suited to experienced hikers and physically fit individuals. Reaching it requires tackling a challenging hike across volcanic terrain characterized by rocks, lava, and significant changes in elevation. Before setting out, it is crucial to check weather conditions and select a route appropriate for one’s fitness level. Recommended gear includes hiking boots, warm waterproof clothing, gloves, a helmet, and a headlamp. Furthermore, the presence of ice and unstable surfaces makes it advisable to rely on an expert guide, especially when exploring the cave’s interior.
During the hike, one must respect the environment, avoiding any damage to the ice, rocks, or other natural features. Mount Etna is a delicate ecosystem, and the Grotta del Gelo stands as an important testament to the volcano’s activity and evolution. Consequently, exploration demands caution, preparation, the presence of an expert guide, and near-professional-grade equipment, but it offers a unique experience amidst volcanic landscapes, snow, and ice in return.