Seen here with its explosive summit socked away in the clouds, Mount Etna towers over the Italian isle of Sicily as the tallest volcano in Europe—and maybe the crankiest, given its near-constant eruptions. The island peak has been highly active for perhaps half a million years and can still be counted on for a spectacular eruption now and then. This photograph shows Etna erupting in 2013, but it blasted back into life again in February 2021, sending lava, ash, and smoke into the sky for weeks.