South in the bay of Naples lies the Mount Vesusius, ominously visible from the city. Few can see the volcano without thinking of the tragedy that took place nearly two thousand years ago - the eruption in 79 AD that buried buildings and people of the Roman cities Pompeii, Herculaneum and Stabiae in lava.
The explosion was quite unexpected. The volcano had been dormant for 1200 years, and the only warnings the Roman unfortunates got were minor tremors in the earth. After the eruption, Vesuvius kept fuming, erupting once every hundred years until the 11th century. People forgot, just as the entombed cities of the Romans were forgotten.
Then a surprise eruption happened in 1631, killing 4000. It was during the clearing and restoration work after this disaster that the buried Pompeii was discovered, its buildings with furniture, signs and frescoes still intact, the victims preserved in shapes of ashes. Ever since then, people living nearby have kept an anxious watch on the mountain, and by now Vesuvius is one of the most studied volcanoes in the world. It is monitored constantly, so as to avoid a repetition of the charcoaled humans, at least.
Today two million people live in the immediate vicinity of Mount Vesuvius. The Campanian government is currently offering those most at risk money to move away from the potentially lethal mountain slopes, planning to develop the area for tourism instead.
Vesuvius is a stratovolcano that follows long cycles of rest and subsequent eruption. The most recent cycle of activity is thought to have ended with eruptions in 1913-1944. Other notable eruptions were the two in 5960 BC and 3580 BC, which are among the largest we know about in Europe in all history.
This department of Vulcan's smithy lies on the site of a much older volcano, Mount Somma, which collapsed some 17 000 years ago. The volcanic hotspot is located above a subduction zone which is created as the plate of the African continent slowly moves towards the north, descends beneath the Eurasian plate, and melts. When the magma wants out, this is where the outlet is.