Mount Etna is more than half a million years old, but this massive stratovolcano in Sicily still has plenty of gas left in the tank. Mount Etna is more than half a million years old, but this massive stratovolcano in Sicily still has plenty of gas left in the tank. The 3,400-meter behemoth is the most active volcano in Europe, often producing several eruptions per year. In fact, E... [3933 chars]