Zannone in the context of "Monte Circeo"

Monte Circeo or Cape Circeo (Italian: Promontorio del Circeo [promonˈtɔːrjo del tʃirˈtʃɛːo], Latin: Mons Circeius) is a mountain promontory that marks the southwestern limit of the former Pontine Marshes, located on the southwest coast of Italy near San Felice Circeo. At the northern end of the Gulf of Gaeta, it is about 5 kilometres (3.1 mi) long by 1.5 kilometres (0.93 mi) wide at the base, running from east to west and surrounded by the sea on all sides except the north. The land to the northeast is the former ancient Pontine Marshes. Most of the ancient swamp has been reclaimed for agriculture and urban areas.

The mountain, the coastal zone as far north as Latina, including the only remaining remnant of the swamp, and two of the Pontine Islands offshore, Zannone and Ponza, have been included in the Circeo National Park.

The Pontine Islands (/ˈpɒntaɪn/, also US: /ˈpɒntiːn/; Italian: Isole Ponziane [ˈiːzole ponˈtsjaːne]) are an archipelago in the Tyrrhenian Sea off the coast of Lazio region, Italy. The islands were collectively named after the largest island in the group, Ponza. The other islands in the archipelago are Palmarola, Zannone,and Gavi to the northwest and Ventotene and Santo Stefano to the southeast. These two groups are separated by 22 nautical miles (41 km). From Sabaudia-Cape Circeo peninsula to Zannone the distance is 12 nautical miles (22 km), while Ventotene faces Gaeta (21 miles). The minimum distance between Santo Stefano and the isle of Ischia is 22 nautical miles (41 km).In ancient times they were called Pontiae (Πόντιαι).

The archipelago is volcanic and has been inhabited for thousands of years. Neolithic artefacts and Bronze Age obsidians have been excavated on the islands. The islands were used by the Etruscans who carved the "Blue Grottos". The earliest recorded history of the islands occurs with the Roman victory over the Volsci at 338 BC. According to a local legend, this was once the lost Kingdom of Tyrrhenia which sank with a narrow strip connected to mainland Italy.

Circeo National Park (Italian: Parco Nazionale del Circeo) is an Italian national park founded in 1934. It occupies a strip of coastal land from Anzio to Terracina, including also a sector of forest in the mainland of San Felice Circeo, and the island of Zannone.

The park was established by order of Benito Mussolini, under advice from Senator Raffaele Bastianelli, to preserve the last remains of the Pontine Marshes which were being reclaimed in that period. It is the only national park in Italy to occupy only a plain and coastal area. It reaches from approximately Pontinia in the north to Sabaudia in the south.

Zannone Lighthouse (Italian: Faro Isola Zannone) is an active lighthouse located in the northern part of Zannone in the Pontine Islands on the Tyrrhenian Sea.