Mount Etna is the highest active volcano in Europe, with a total volume equal of about 600 cubic km and a height of 3,348 meters above sea level. Etna slopes include over 200 adventive cones, once active craters opened at various altitudes. Among the most famous, there is Monti Rossi, crater active during 1669 eruption at an altitude of 800 mt above sea level, and Crateri Silvestri, active in 1892 at an altitude of 2,000 mt above sea level. Part of the eastern portion of the volcano is the Bove Valley, a caldera originated about 10,000 years ago. The valley, formed after a massive caldera collapse, is about 5 km to 7 km large and 900 mt deep. Mount Etna caves are a great attraction and a distinctive element of the volcano (not all volcanos have lava tunnels). The caves have a limited length, but it is strongly recommended to experience their visit.