Etna or Aetna (both: ĕtˈnə) [key], volcano, 10,958 ft (3,340 m) high, on the east coast of Sicily, S Italy. It is the highest active volcano in Europe. The shape and height of its central cone have often been changed by eruptions. There are more than 260 lesser craters on the slopes, formed by lateral eruptions. The southeastern slope is cut by a deep (2,000–4,000-ft/610–1219-m), precipitous cleft, the Valle del Bove. The first known eruption occurred in 475 B.C. and was described by Pindar and Aeschylus. Of the numerous later eruptions, often accompanied by earthquakes, those of 1169 and 1669 were the most destructive; the most recent major eruption occurred in 1992.
The wide base of Mt. Etna, c.93 mi (150 km) in circumference, is encircled by a railroad. The fertile lower slopes are densely populated agricultural areas. Up to 1,600 ft (488 m) the vegetation is subtropical, yielding citrus fruit, bananas, and figs; between 1,600 and 4,300 ft (488–1,311 m) is a temperate zone, with vineyards and various fruit trees; from there to c.7,000 ft (2,130 m) are chestnut, birch, and pine woods; above, there is a desolate waste of lava and ashes. Near the top there is snow most of the year. There is an observatory at 9,650 ft (2,941 m). A motor road from Nicolosi, NW of Catania, to the 6,170-ft (1,881-m) level was completed in 1935.