Pozzuoli in the context of "Phlegraean Fields"

Pozzolana or pozzuolana (/ˌpɒts(w)əˈlɑːnə/ POT-s(w)ə-LAH-nə, Italian: [potts(w)oˈlaːna]), also known as pozzolanic ash (Latin: pulvis puteolanus), is a natural siliceous or siliceous-aluminous material which reacts with calcium hydroxide in the presence of water at room temperature (cf. pozzolanic reaction). In this reaction insoluble calcium silicate hydrate and calcium aluminate hydrate compounds are formed possessing cementitious properties. The designation pozzolana is derived from one of the primary deposits of volcanic ash used by the Romans in Italy, at Pozzuoli. The modern definition of pozzolana encompasses any volcanic material (pumice or volcanic ash), predominantly composed of fine volcanic glass, that is used as a pozzolan. Note the difference with the term pozzolan, which exerts no bearing on the specific origin of the material, as opposed to pozzolana, which can only be used for pozzolans of volcanic origin, primarily composed of volcanic glass.

The Gulf of Naples (Italian: Golfo di Napoli; Neapolitan: Gurfo 'e Napule), also called the Bay of Naples, is a roughly 15-kilometer-wide (9.3 mi) gulf located along the south-western coast of Italy (Metropolitan City of Naples, Campania region). It opens to the west into the Mediterranean Sea. It is bordered on the north by the cities of Naples and Pozzuoli, on the east by Mount Vesuvius, and on the south by the Sorrento Peninsula and the main town of the peninsula, Sorrento. The Peninsula separates the Gulf of Naples from the Gulf of Salerno, which includes the Amalfi Coast.

The islands of Capri, Ischia and Procida are located in the Gulf of Naples. The area is a tourist destination, with the seaside Roman ruins of Pompeii and Herculaneum at the foot of Mount Vesuvius (destroyed in the AD 79 eruption of Vesuvius), along the north coast.

Cumae (Ancient Greek: Κύμη, romanized: (Kumē) or Κύμαι (Kumai) or Κύμα (Kuma); Italian: Cuma) was the first ancient Greek colony of Magna Graecia on the mainland of Italy and was founded by settlers from Euboea in the 8th century BCE. It became a rich Roman city, the remains of which lie near the modern village of Cuma, a frazione of the comune Bacoli and Pozzuoli in the Metropolitan City of Naples, Campania, Italy. The archaeological museum of the Campi Flegrei in the Aragonese castle contains many finds from Cumae.

Cape Miseno (Italian: Capo Miseno, Latin: Misenum, Ancient Greek: Μισήνον) is the headland that marks the northwestern limit of the Gulf of Naples as well as the Bay of Pozzuoli in southern Italy. The town of Miseno is located on the north side of the cape. It is the location of the Capo Miseno Lighthouse.

The cape is directly across from the island of Procida and is named for Misenus, a character in Virgil's Aeneid.

Solfatara (Italian: Solfatara di Pozzuoli) is a shallow volcanic crater at Pozzuoli, near Naples, part of the Phlegraean Fields (Italian: Campi Flegrei) volcanic area. It is a volcano, which emits jets of steam with sulfurous fumes. The name comes from the Latin, Sulpha terra, "land of sulfur", or "sulfur earth". It was formed around 4000 years ago and last erupted in 1198 with what was probably a phreatic eruption – an explosive steam-driven eruption caused when groundwater interacts with magma. The crater floor was a popular tourist attraction until 2017, as it has many fumaroles and mud pools. The area is well known for its bradyseism. The vapours had been used for medical purposes since Roman times.

This volcano is where the thermoacidophilic archaeon Sulfolobus solfataricus was first isolated. The archaeon is named for the volcano, as most species of the genus Sulfolobus are named for the area where they are first isolated.

Lake Avernus (Italian: Lago d'Averno) is a volcanic crater lake located in the Avernus crater in the Campania region of southern Italy, around 4 kilometres (2+1⁄2 miles) west of Pozzuoli. It is near the volcanic field known as the Phlegraean Fields (Campi Flegrei) and comprises part of the wider Campanian volcanic arc. The lake is roughly circular, measuring two kilometres (1+1⁄4 mi) in circumference and 60 metres (200 ft) deep.