Cape Circeo in the context of "Gulf of Gaeta"

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.

Ponza (Italian: isola di Ponza [ˈiːzola di ˈpontsa]) is the largest island of the Italian Pontine Islands archipelago, located 33 km (21 mi) south of Cape Circeo in the Tyrrhenian Sea. It is also the name of the commune of the island, a part of the province of Latina in the Lazio region.