Mount Vesuvius is a stratovolcano in the Gulf of Naples. It is one of several volcanoes which form the Campanian volcanic arc. Vesuvius consists of a large cone partially encircled by the steep rim of a summit caldera caused by the collapse of an earlier and originally much higher structure.
Mount Vesuvius is best known for its eruption in AD 79,  one of the most catastrophic and famous eruptions of all time, that led to the burying and destruction of the Roman cities of Pompeii and Herculaneum. That eruption ejected a cloud of stones, ash and fumes to a height of 20.5 miles, spewing molten rock and pulverized pumice.
Vesuvius has erupted many times since and is the only volcano on the European mainland to have erupted within the last hundred years.