Regno di Nettuno includes the sea surrounding the Phlegrean Archipelago, formed by the islands of Ischia, Procida and Vivara.
The three islands, closing the Gulf of Naples to the west, are part of a large volcanic complex that is still considered to be active. A sign of this nature that combines water and fire are the many thermal springs, exploited today in a series of spas and wonderful gardens, that link swimming pool complexes at different temperatures to the real botanical gardens.
The island of Ischia, with few but beautiful beaches, is extremely marked by greenery, rich in sheer cliffs, coves, and sea caves.
Procida is the second largest island in the Phlegrean archipelago. Resulted from an ancient explosion, it is located in a junction between the great volcanic caldera of the Phlegrean Fields and that of the island of Ischia. A harsher island in apparence, it is characterised by high cliffs and reflects in its structure the rough but Mediterranean character of the islanders. Nevertheless, it displays to people who arrive there a colourful and sunny atmosphere that is in contrast with the harshness of its rocky appearance.
Vivara is the smallest island. It has been uninhabited for a long time and is a State Nature Reserve of great importance for the European environment.