Drilling is underway at the site of a huge underground volcano near the Italian city of Naples, a few kilometres from Vesuvius.
Scientists are looking for a chamber of molten rock believed to be located 3.5 km underground in the Campi Flegrei region.
This type of volcanic land is known to be the origin of the strongest type of eruptions, capable of causing a level of destruction similar to that of a meteor striking earth.
But the head of the drilling project says it is rare
for these areas to erupt at their full capacity.
Around three million people live in the Campi Flegrei region, which lies north west of Naples.