Valle del Bove

Etna's eastern side opens into a colossal horseshoe depression roughly seven by four and a half kilometres across, its floor paved by lava flows from later flank eruptions. Born of gigantic slope collapses radiocarbon-dated to prehistory, the Valle del Bove is the volcano's great open archive, its walls exposing thousands of years of eruptive history.

Why it matters

UNESCO's inscription of Mount Etna on the World Heritage List in 2013, under criterion (viii) for ongoing geological processes, explicitly names the Valle del Bove depression among the features that justify the volcano's outstanding value. The recognition is deserved. The valley is the dominant landform of Etna's eastern flank, a textbook record of how a large volcano can lose a whole sector of its body, and a research subject that still produces firsts: in 2023 an INGV team working with the University of Urbino published the first absolute dates for the valley's formation.

What to notice

Seen from above, the shape explains itself: an amphitheatre about seven by four and a half kilometres wide, open toward the Ionian Sea and cut into the volcano's eastern shoulder. INGV describes the floor as entirely covered by lava erupted from flank vents over recent centuries, so the surface you look at is geologically very young. The inner walls are the real exhibit. There the collapse sliced through older volcanoes, exposing dyke systems — the frozen plumbing of Etna's precursors — and the products of the Ellittico volcano along the northern wall. On the coast below, debris loosened by the collapse was later reworked into the Chiancone, a broad alluvial fan facing the sea.

Context and history

INGV's account of Etna's geological evolution places the valley's birth around 10,000 years ago, when a series of great landslides tore open the eastern flank of the Mongibello volcano, the edifice built after the older Ellittico centre. The evidence is dramatic: the Milo debris deposit, outcropping near the town of that name, covers 4.3 square kilometres. In January 2023, INGV and the University of Urbino announced that tree fragments preserved inside the landslide deposit, dated by radiocarbon, fix the start of the collapse between 7478 and 7134 BC. The same study, published in the Journal of Volcanology and Geothermal Research, used palaeomagnetic dating to reconstruct later flank eruptions from the valley, including two in the late Copper Age between 2600 and 2400 BC, and two more — in Greek-Roman and medieval times — absent from every historical record. Long before the collapse, the area already held a central role: around 110,000 years ago the so-called Valle del Bove eruptive centres, including the large Trifoglietto volcano, grew on the very ground the depression now occupies.