The huge Etna Volcano was formed hundreds of thousands of years ago from the overlapping of four different volcanoes. Today its height stands at 3323 m. About 500.000 years ago, there was a large gulf in the Ionian sea where the mount Etna is situated now. In its center, after a long period of underwater volcanic activity, the first subaerial volcanoes emerged. The most important, Calanna, close to the village of Zafferana Etnea, is nowadays extinct.
When Calanna finished its activity and its slopes were eroded, about 80.000 years ago, a new volcano called Trifoglietto I started its new violent eruptive activity. A few thousands years later, Trifoglietto II was born in succession. These two new volcanoes covered the remainings of the old Calanna and extended its slopes in the gulf. About 64 thousands years ago, tremendous explosions emptied the magma chamber that fed the Trifoglietto I and Trifoglietto II volcanoes, collapsing therefore the craters and generating the charming Bove Valley, a huge and desolate volcanic caldera that stretches over 5 km. After this disaster, the activity ceased for 30 thousands years.
Volcanic activity resumed 34 thousand years ago with the opening of an eruptive cone situated at the West of the former volcanoes. Thus the Mongibello Volcano was born (which is currently active in this region). Thanks to the the huge amount of erupted lava, Mongibello definitively welded the whole Etna volcanic mass with the east coast of Sicily. Even today, the majestic Mongibello (usually called Etna), characterised by a fluid volcanism and therefore relatively safe, frequently erupts from the summit mouths or lateral craters, often putting at risk houses, woods and cultivated fields.