#phlegraean fields

Naples and Mount Vesuvius at night (Italy, January 2017), from the International Space Station.

The different colours of lights are because of the history of development in the region. The green lights are mercury vapour bulbs, and in some places they have been replaced by orange sodium bulbs, which give off a yellow-orange light.  In the north-east of the photo, agricultural fields are dark between the homes and businesses.

The black circular area is Mount Vesuvius, which is Europe's only active mainland volcano. It is a stratovolcano, which means that it is made up of various materials (pyroclastic flows, lava flows, and debris from lahars) that have accumulated to create the volcanic cone.  Vesuvius is one of the most heavily-monitored volcanoes in the world, with several dozen sensors on and around the cone.

Vesuvius is part of the Campanian volcanic arc, which includes the Phlegraean Fields and Mount Etna (in Sicily).

Statue of a Goddess

From Rione Terra, Pozzuoli. 1st cent AD.

Lake Avernus (Lago d’Averno) and the Cave of the Sibyl, Naples, Campania, Italy.

Avernus is a volcanic lake sited in the Phlegraean Fields and whose name derives from the Greek “άορνος” (without birds) because in Greek mythology the waters of the lake exhaled gases harmful to avian life. This deep lake (213 ft / 60 m deep) was seen as the gateway to the underworld and associated with hell, Hades, in Roman mythology. Even the great poet Virgil, in the Aeneid, identifies the lake as the entrance from which the fearless Aeneas must go to enter hell.