The Campi Flegrei caldera was formed 40.000 years ago. According to one theory the explosion that formed it was so big that played a key role in the extinction of the Neanderthals…
The supervolcano is located opposite to Vesuvius, that destroyed Pompeii, and it shows signs of activity. A possible explosion could affect at least half a million people as the area of Napoli is populated by almost 3 million people. This makes any decision very difficult for the authorities. In the 13 km of the caldera there are 24 craters, most of them underwater.
However, scientists say that it is still not clear if or when the supervolcano could erupt, but underline that if it does it will be extremely dangerous for the local population. The last eruption was relatively small and took place in 1538, forming a small hill called Monte Nuovo.
The activity was first detected in 2005 and in 2012 the threat level was upgraded from Green (idle) to Yellow (attention).