The summit craters of Mount Etna: names, formation and altitude

There is a point, as you climb towards the top of Etna, where the landscape changes its very nature. The vegetation disappears, the ground becomes an expanse of ash and scoria, the wind carries the sharp smell of volcanic gases. Ahead of you appear the summit craters of Etna: the active vents that occupy the highest part of the volcano and continually reshape its profile.

They are not simply hollows opened at the top. They are structures born in different eras, fed by a volcanic system in motion and shaped by explosions, collapses and accumulations of erupted material. Knowing their names helps you understand what you see up close, and also what stands out from Catania, Taormina and the villages around the volcano on clear days.

What are the summit craters of Etna: the short answer

There are four main summit craters:

1. North-East Crater, born in 1911;
2. Voragine, formed in 1945 inside the Central Crater;
3. Bocca Nuova, opened in 1968, also within the Central Crater;
4. South-East Crater, born in 1971 and enlarged by numerous eruptive episodes.

Their altitude is not fixed. The summit area lies roughly between 3,300 and 3,400 metres, but the highest point can change after an eruptive phase or a collapse. It is one of the most fascinating things about Etna: the summit you see today is not exactly the one from a few years ago, and it will not be identical to the one in the future.

The names of Etna's four craters

Until the early twentieth century the summit looked very different from today. The four structures we recognise now all formed within the last hundred and twenty years or so: an extremely short interval compared with the geological history of the volcano, which began hundreds of thousands of years ago.

The North-East Crater

The North-East Crater has existed since 1911. For many decades its rim was the highest point of Etna, and its cone became one of the most recognisable features of the summit profile.

Its activity alternates between degassing, explosions and periods of apparent quiet. That last word should be used with caution: on an open-conduit volcano, the absence of spectacular phenomena does not mean the absence of deep dynamics.

The Voragine

The Voragine opened in 1945 inside the old Central Crater. Its name — Italian for "chasm" — captures the impression this vast depression makes, but its shape does not stay the same. The build-up of scoria and volcanic bombs can construct new inner cones; explosions and subsidence can widen or lower its rims.

Eruptions from the Voragine have shown how quickly the morphology of the summit can change. This is why, whenever the altitude of Etna is mentioned, the date of the survey must always be given as well.

The Bocca Nuova

The Bocca Nuova appeared in 1968 next to the Voragine, again inside the Central Crater. It is an intricate system, marked by inner walls, fractures, degassing vents and areas that can be modified or filled in by the products of nearby eruptions.

Degassing can be intense even when no lava flows or fountains are visible. The plume rising from the summit, often loosely described as “smoke”, consists mainly of water vapour and volcanic gases.

The South-East Crater

The South-East Crater is the youngest. Born in 1971 on the eastern flank of the Central Crater, it grew rapidly through numerous paroxysms — brief, highly energetic explosive episodes, often accompanied by lava fountains, fallout of pyroclastic material and lava flows.

Its evolution also includes the so-called New South-East Crater, which developed from a vent that opened on the flank of the earlier cone. Today the whole forms a complex and highly dynamic structure, overlooking the Valle del Bove.

The website of the INGV Etnean Observatory offers a scientific description of the four craters and of the volcano's activity.

How high are the summit craters

Saying that Etna is a precise number of metres tall is convenient, but it does not tell the whole truth. The summit is a natural building site: every eruption can lay down new layers of lava and scoria, while explosions, landslides and collapses can remove material.

This is why the altitude is updated through topographic surveys, satellite imagery, drones and digital terrain models. In practical terms, the summit crater area sits above 3,300 metres, with rims that can approach 3,400 metres. Which structure holds the record has changed several times over the years.

The altitude also has concrete consequences for anyone climbing:

• the temperature can be far lower than on the coast;
• the wind can pick up quickly;
• solar radiation is intense even when the air is cold;
• less available oxygen makes walking more tiring;
• cloud and fog can cut visibility within minutes.

Etna's “moving” summit is therefore not just a geological curiosity. It is the reason why route, equipment and conditions have to be assessed every single time.

How the summit craters form

Beneath the summit, magma rises through a system of conduits and fractures. As it rises the pressure drops and the gases dissolved in the magma tend to separate — a process comparable, with all due differences, to what happens when you open a fizzy drink.

If the gases escape fairly steadily, what you see from the top is mainly degassing. If instead they build up and expand rapidly, they can fragment the magma and produce explosions. The ejected material falls back around the vent and, layer after layer, builds cones and crater rims.

The shape of a crater therefore depends on an always provisional balance between two processes:

• construction, from the accumulation of lava, scoria, lapilli and bombs;
• destruction, caused by explosions, landslides and collapses of the inner walls.

This is why the summit craters look nothing like four neat bowls. They are a complex landscape of ridges, depressions, fractures, overlapping cones and surfaces in different colours.

What activity can you see at the top

Etna's activity can take different forms. The most common is persistent degassing, visible as a white or grey plume. In other periods there are Strombolian explosions: intermittent jets of incandescent material that falls back near the vent.

More intense episodes can evolve into lava fountains, ash columns and lava flows. There are also flank eruptions, fed by fractures that open on the sides of the volcano, sometimes far from the summit.

This variety explains why Etna is one of the most studied volcanoes in the world. It also explains why no itinerary is guaranteed in every season and every phase: what is accessible depends on volcanic activity, weather, visibility and the ordinances in force.

What you see on a hike to the summit craters

Reaching high altitude means crossing very different environments in a few hours. On the north side you start from Piano Provenzana and enter the theatre of recent eruptions, among dark flows, cones and wide open spaces. The 4×4 transfer lets you gain altitude before the walking section.

When conditions allow you to approach the summit area, the landscape changes with every step: the ground can shift from black to the red and yellow of alteration, the sound of the gases becomes sharper and the view opens towards the Valle del Bove, the Ionian coast, Taormina and the Aeolian Islands.

The value of the experience is not only in getting high. A volcanological guide helps you read what would otherwise look like an undifferentiated expanse: a fracture, a volcanic bomb, the edge of a lava flow, the difference between a summit crater and a flank cone.

Can you visit the summit craters of Etna

Yes, but access should not be taken for granted. Etna is an active volcano and the summit area is a high-mountain environment. Limits, permitted routes and reachable altitudes can change according to ordinances and the real situation on the ground.

Before departure, the following are assessed:

• volcanic activity and guidance from the competent authorities;
• weather, wind and visibility;
• ground conditions;
• the fitness level and equipment of participants;
• any changes to the route.

For an up-to-date picture you can check the real-time Etna monitoring. The data is an informational tool: the guide's operational decision and the instructions of the authorities always take priority.

Getting to know the summit before you climb it

The summit craters tell the story of Etna better than any definition: a mountain that grows, collapses and rebuilds itself while we watch. Seeing them with a guide means joining the landscape to its history, and tackling high altitude with an itinerary suited to the conditions of the day.

If you want to work out which experience to choose, discover the summit craters trek and the other guided hikes on Etna. Tell us your date, the number of participants and your fitness level, and you will get advice on the route that suits you best.