The Bay of Naples with Mount Vesuvius in the background.  Note where the top was blown off in the AD 79 eruption.  It is best known for that  eruption which led to the destruction of the Roman cities of Pompeii and Herculaneum and the death of 10,000 to 25,000 people. It has erupted many times since and is today regarded as one of the most dangerous volcanoes in the world because of the population of 3,000,000 people living nearby and its tendency towards explosive (Plinian) eruptions.