Two thousand years ago Mount Vesuvius destroyed Pompeii. Today, a larger, far more deadly supervolcano lurks on the other side of Naples. If it erupts, Campi Flegrei could wipe out all life in Europe. So why are British scientists battling the Italians for the right to poke at it with drilling rods?

The caldera, which now is essentially at ground level, is accessible on foot. It contains a large number of fumaroles, from which steam can be seen issuing, and over 150 pools of boiling mud at last count. Several subsidiary cones and tuff craters lie within the caldera. One of these craters is filled by Lake Avernus. In 1538, an eight-day eruption in the area deposited enough material to create a new hill, Monte Nuovo. It has risen about 2 metres (7 ft) from ground level since 1970. It is a volcano capable of producing VEI 7 eruptions, as large as that of Tambora in 1815.[7] At present, the Campi Flegrei area comprises the Naples districts of Agnano and Fuorigrotta, the area of Pozzuoli, Bacoli, Mount Procida, Quarto, the Phlegrean Islands (Ischia, Procida and Vivara).Recent inflation of the caldera centre in the vicinity of Pozzuoli may presage an eruptive event within decades