The Italian supervolcano that mythology claims is a gateway to hell

Space · Published 27 October 2026 Swipe more like this →

In short: Deep beneath the densely populated region of Pozzuoli, an ancient caldera is stirring with seismic activity not seen in centuries. While it poses a massive threat to over half a million people, the question remains: is this a looming catastrophe or merely a restless giant?

The Phlegraean Fields (Campi Flegrei) are often labeled a 'supervolcano'—a term originally coined in the 1940s to describe American sites like Yellowstone. While it shares scale with these giants, its behavior is distinct. The caldera is characterized by explosive eruptions of small to medium size, rather than the massive effusive flows seen elsewhere. Despite its status as a 'national threat,' scientists currently categorize the volcano as being in a state of quiescence, meaning there is no active eruption despite significant ground movement.

The danger is rooted in the sheer scale of potential impact. The volcanic area covers an eight-mile-wide crater where over 500,000 people reside within a designated 'red zone.' If a major eruption occurs, it could produce pyroclastic flows—super-heated clouds of ash and particles reaching temperatures of 1,472 degrees Fahrenheit. These flows can travel at speeds between 30 and 60 miles per hour. Furthermore, an eruptive column could rise up to 18 miles into the sky, with falling debris heavy enough to collapse residential roofs.

Monitoring is intense but the stakes are high; there are no known countermeasures to protect against such flows once they begin. The National Institute of Geophysics and Volcanology in Naples maintains a direct line to Rome's civil protection headquarters, tested twice daily. This vigilance follows a history of alarming activity, including a 3-meter ground uplift in 1983 that led to evacuations but resulted in no eruption. Today, recent earthquakes in March and June have caused significant structural damage, leaving some families unable to return home.

The area is steeped in cultural significance, with Greek and Roman mythology depicting the Campi Flegrei as an opening to the underworld. This mythological weight mirrors the geological reality: prehistoric eruptions were so powerful they reportedly blocked out the sun and covered vast portions of Europe and Russia in ash.

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