Phlegraean Fields

The Phlegraean Fields are an active volcanic area with a structure called "caldera" : a low-lying area with an almost circular shape that was formed as a result of large explosive eruptions. The Phlegraean Fields caldera extends from Monte di Procida to Posillipo and also includes an underwater part in the Gulf of Pozzuoli. More than 70 eruptions have occurred over the past 15,000 years, forming volcanic edifices, craters and volcanic lakes that are still clearly visible, such as Astroni, the Solfatara and Lake Averno.
The last eruption dates back to 1538. Since then, the area has been characterised by fumaroles, repeated episodes of ground deformation (bradyseism) and earthquakes.