The islands Known as the Seven Pearls of the Mediterranean

We are bobbing up and down on a boat in the middle of the Tyrrhenian Sea, having a science lesson about volcanoes from two American high school teachers, when suddenly Stromboli erupts.

It is a sight to behold. White smoke billows skyward from its 926-metre-high peak and our two teachers, Barb Orth and Marian Hoskins, are besides themselves with joy. We all gaze drop-jawed at the cauldron of fire and real brimstone.

“Stromboli is like the Holy Grail for science teachers,” says Orth in her delightful Southern twang. “It’s like a Catholic going to the Vatican.”

The rest of us hang off their every word whilst they point to the yellow line on the volcano, which they call the sulphur line. They explain how hot, quick-flowing magma from deep beneath the Earth’s surface rises, collects in magma chambers and bursts forth to the surface like a giant belch through vents and fissures.