The Bove Valley is a vast depression situated on the eastern side of Mt Etna, whose walls in some points exceed 1000 m. Its origin is very debated and complex: according to recent studies it is due to the coalescence of various caldera collapses that occurred during the evolution of the volcano Etna. The first of this collapses, that of the Calanna eruptive centre, took place about 100.000 years ago, while the last of a certain importance, that of the Leone eruptive centre, about 8.000 years ago. It seems that around 5.000 years ago there were other collapses in the central part of the western wall of the valley. In the 18th century, the Bove Valley was a wooded zone belonging to the Archbishops of Catania, but from 1792 a series of great and small eruptions covered its bottom with a-a type lava flows.
At the moment, it is an immense extension of lavas with remains of ancient eruptive centres (Rocca Musarra, Monte Calanna). Numerous eruptions have occurred inside this valley, particularly along the western wall: 1792, 1802, 1811 (Monte Simone), 1819, 1838, 1842, 1852-53 (Monti Centenari), 1869, 1908, 1950-51, 1956, 1964, 1968, 1971, 1978, 1979, 1984, 1985, 1986-87 (Monte Rittmann), 1989, 1991-93; only the lava flows of 1852-53, 1950-51, 1979 managed to overflow the limits of the valley and reach inhabited areas, while the lava flows of the other eruptions stopped inside the valley.
For this reasons, the Bove Valley is considered an enormous, limitless natural tank able to receive all the lava produced by the almost continuous eruptive activity of Mongibello. On the walls of the valley, the lava flows and superposed pyroclastic material (ash, scoriae, bombs, etc.) tell us the story of the evolution of the existent eruptive centres before the current active volcano Mongibello; one of this, Trifoglietto, at the end of its activity and after violent explosive events, collapsed leaving the present Piano del Trifoglietto. In addition, on the walls of the valley, numerous dikes emerge (feeders laid bare by erosion), as witness of so many eruptions. The prevalent NNW-SSE, ENE-WSW and NE-SW directions of these dikes show the main channels for the return of magmas in the volcano.