It is a composite volcano formed from the debris of previous eruptions.
Viewed across the Gulf of Naples from Sorrento, the volcano dominates the bay.
The 79AD eruption was explosive. Pyroclastic deposits of pummice dust spread high and wide. This a sulphurous gases suffocated the population of Pompeii.
The steep volcanic cone collapsed leaving a crater 11km wide. Known known as Mount Somma it is 1132m high.
It is a composite volcano formed from the debris of previous eruptions.
Inside this creater subsequent eruptions in 1139, 1691, 1707, 1794, 1895, 1899, 1906 and 1944 created the inner cone and crater which stands at 1277m.
The volcano is still dangerous, a single plume of steam can still be seen.
Over 3 million people live in the shodow of the volcano.
The rich volcanic soil is very fertile and vineyards, citrus groves flourish along with Oak and Beech forests.
Now a national park, buses take you into the inner crater to 1000m. From there it is a walk up a steep winding path to the crater lip.
Back in 1971 when I last visited there was a chairlift to the top, this has long since collapsed down the slopes. All that remains are the anchor points.
Magnificant views over the Bay of Naples, Naples, Herculaneum, Pompeii and Sorrento.
The islands of Capri Ischia and Procida can be seen out in the bay.
All images © Ian Foster / fozimage