Campi Flegrei del Mar di Sicilia is a field of submarine volcano

Submarine volcano

Submarine volcanoes are underwater fissures in the Earth's surface from which magma can erupt. They are estimated to account for 75% of annual magma output. The vast majority are located near areas of tectonic plate movement, known as ocean ridges...

es located south-west of Sicily

Sicily

Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...

. It includes the vent of Ferdinandea

Ferdinandea

Ferdinandea is a submerged volcanic island which forms part of the underwater volcano Empedocles, south of Sicily, and which is one of a number of submarine volcanoes known as the Campi Flegrei del Mar di Sicilia. Currently a seamount, eruptions have raised it above sea level several times...

, otherwise known as Graham Island, which erupted and emerged above sea level in 1831, and encompasses a larger volcano known as Empedocles

Empedocles (volcano)

Empedocles is a large underwater volcano located 40 km off the southern coast of Sicily named after the Greek philosopher Empedocles who believed that everything on Earth was made up of the four elements....

. The last recorded eruption was in 1867, from a vent named Pinne. There was mild seismic unrest at Ferdinandea

Ferdinandea

Ferdinandea is a submerged volcanic island which forms part of the underwater volcano Empedocles, south of Sicily, and which is one of a number of submarine volcanoes known as the Campi Flegrei del Mar di Sicilia. Currently a seamount, eruptions have raised it above sea level several times...

in 2000 - 2002. At its highest, Campi Flegrei comes to 8 meters (26 feet) below sea level.