Mount Vesuvius crater | Inside the heart of the volcano

Mount Vesuvius, the volcano near Naples, Italy, is a stratovolcano formed from two separate volcanoes. At the cone’s summit is a crater that’s 1,000 feet deep, created from countless eruptions over the years, with the most notorious one being in 79 AD, which buried Pompeii and Herculaneum.

What is a crater?

The crater is the bowl-shaped depression at the top of a volcano where the eruption happens. The Vesuvius crater lets you see this volcanic landscape up close and enjoy some incredible panoramic views of the surrounding area, including the Bay of Naples.

Crater vs Caldera

Mount Vesuvius has a crater rather than a caldera. A crater is a smaller, bowl-shaped depression at the summit of a volcano formed by explosive eruptions, like the one at Vesuvius created by past eruptions. In contrast, a caldera is a much larger depression that forms when a volcano’s summit collapses into a partially emptied magma chamber, often after a massive eruption. While Vesuvius’s crater is prominent, a caldera would be much larger and more expansive.

What you’ll see at the crater’s edge

The first thing that captures your attention at the crater’s edge is the vast, rugged expanse of the crater itself. This deep, gaping bowl, carved out by centuries of volcanic activity, stands as a stark reminder of the immense forces that have shaped this landscape. The crater’s edges are jagged and raw, revealing layers of volcanic rock and ash along its steep walls. The contrast between the dark, almost black basalt and the lighter ash deposits highlights the complexity of this geological wonder.
As you stand on the rim, the energy of the volcano beneath your feet is palpable. Though Mount Vesuvius is currently dormant, fumaroles—small openings in the earth that release steam and gases—serve as a reminder that this is still a living, breathing volcano. These fumaroles emit wisps of steam that curl into the air, adding an eerie, almost surreal element to the scene.
But it’s not just the crater that will take your breath away. The panoramic views from the summit are nothing short of spectacular. On a clear day, you can see for miles in every direction. The Bay of Naples stretches out before you, its deep blue waters contrasting sharply with the stark, volcanic landscape of Vesuvius. In the distance, the bustling city of Naples lies in contrast to the serene blue of the bay, while the islands of Capri and Ischia rise from the sea like jewels in the Mediterranean.

Mount Vesuvius crater | A breakdown of its formation

• Explosive eruptions: The most significant eruption that shaped the Vesuvius crater occurred in 79 AD. This catastrophic eruption expelled a massive amount of volcanic material, including magma, ash, and gasses, with such force that it blew off the top of the volcano. This explosion created the initial bowl-shaped depression at the summit, which is the crater we see today.
• Summit collapse: Following the explosion, the central part of the volcano, weakened and partially emptied of magma, collapsed inward. This collapse deepened the depression and further defined the crater's shape.
• Subsequent activity: Over the centuries, Vesuvius has had additional eruptions and volcanic activity that modified the crater’s appearance. New layers of volcanic deposits have built up around the crater, but the basic bowl shape created by the 79 AD eruption remains the prominent feature.