Vesuvius, a volcano in southern Italy near the eastern shore of the Bay of Naples, about eight miles (13 km) southeast of the city of Naples. The summit of the cone is 4,190 feet (1,277 m) above sea level. An extinct crater, Mount Somma (3,714 feet [1,132 m]), forms a ridge on the north slope of Vesuvius. It is separated from the newer cone by a deep valley.

The lower slopes of Vesuvius are covered with vineyards, gardens, and citrus groves. There are villages on the slopes and on the plains at the foot of the mountain. A seismological observatory, built in 1845, is on the west slope.

Mount Somma is believed to have been formed more than 13,000 years ago, and was largely destroyed in a violent explosion. Vesuvius later formed within the crater left by the explosion.

The first recorded eruption of Vesuvius took place in 79 A.D. This eruption destroyed the towns of Pompeii and Herculaneum, burying them in ash and other material ejected from the volcano. A detailed account of the event was written by the Roman author Pliny the Younger. His uncle, Pliny the Elder, was killed by poisonous gases from the eruption.

More than 30 eruptions of Vesuvius have occurred since that time. One of the most destructive of these eruptions took place in 1631, when most of the villages at the foot of the volcano were destroyed. A major eruption in 1906 also destroyed a number of villages. The most recent eruption of Vesuvius occurred in 1944. This eruption destroyed the villages of San Sebastiano and Massa.

Thousands of people visit Vesuvius each year. A paved road extends beyond the seismological observatory to a point from which the crater can be reached by a short trail.