The first erupted volcano was Vesuvius. Vesuvius is a volcano on the west coast of Italy, southeast of Naples. The name "Vesuvius" is derived from the Oscan "fesf", meaning smoke. The volcano is located in the plains of Campania, has a diameter of eight kilometers and is 1281 meters high. Vesuvius is located in the caldera of an older volcano, the Somma. The caldera was formed about 18 300 years ago. This (a volcano in a caldera) is sometimes called summations volcano. Vesuvius is a stratovolcano; strato- derives from stratum, Latin for 'low'. A stratovolcano consists of an alternation of layers of ash and cinder, which are formed in the two stages of an eruption of the volcano type.