The supervolcano Campi Flegri, or “burning fields” in Italian, which is located near Naples, is showing signs of activity after lying dormant for almost 500 years.
The 12 km-wide cauldron is releasing increasing amounts of carbon monoxide and boiling mud. Small tremors can also be felt around the area.
The region has only had two major eruptions, 35,000 years ago and 12,000 years ago.
A “smaller” explosion occurred in 1538: it lasted eight days and formed the Monte Nuovo mountain.
The Campi Flegri has become restless over the past 60 years, most notably in 1983-84 when the ground surrounding the mountain rose by almost 6 feet.
In 2012, Italian authorities raised the threat level from green to yellow, meaning that the area requires scientific monitoring.
An hour’s drive from the infamous Mount Vesuvius, the supervolcano is said to have contributed to the demise of Neanderthals in Europe.
The area is now a regional park, filled with hot springs and geysers as well as being home to more than 500,000 people.
Scientists say it is impossible to predict exactly what is going to happen in the region but many fear the worst.