The incredible European city that's 'emerging from the sea' after sinking 2,000 years ago

The ruins of an ancient Roman city, which have stayed hidden beneath the waves of the Tyrrhenian Sea for some 2,000 years, are finally being brought back to the surface through underwater tours and ongoing excavations. A volcanic eruption is believed to have sunk the city of Aenaria, which now lies several feet below Cartaromana Bay off a village on the beautiful island of Ischia, Italy.

Unlike Mount Vesuvius, which devastated the city of Pompeii in 79 AD and was documented by Pliny the Younger, there are no records of the explosion and very little about Aenaria itself. For some 2,000 years, there was no physical trace of it either, as the ruins remained hidden beneath layers of sediment and volcanic material. The first hints of its existence emerged in 1972, when two scuba divers discovered Roman-era pottery shards and two lead ingots off Ichia's eastern shore. However, it then took another 40 years for the ruins of the huge ancient quay to be revealed in 2011.

Each summer, tourists are offered the rare chance to explore the ruins for themselves via 70-minute glass-bottomed boat tours and snorkelling and scuba excursions. All tours begin with the viewing of a 20-minute 3D video in the Marina di Sant'Anna cooperative's auditorium, during which artefacts from the site are displayed beneath glass flooring and a submarine takes you through a digitally reconstructed Aenaria.

According to Ischia Insider, prices start from around €30 per person for boat tours and around €40-45 for snorkelling and diving experiences. Reservations are mandatory. During the cruise, visitors also get the chance to see the village of Ischia Ponte from the sea, as well as the impressive Aragonese Castle, Michelangelo's Tower, churches, and other historic buildings.

Founded in the 4th century BC, Aenaria was a thriving Roman citadel before it was suddenly abandoned between 130 and 150 AD when the Cretaio volcano violently erupted and tsunamis completely engulfed it. The settlement was built around a large port and several boundaries that boasted luxurious coastal villas with statues, columns, mosaics and frescoes.

"The name was documented," local resident Giulio Lauro told BBC Travel. "But no one could find the place." For decades, archaeologists focused on searching for signs of Roman life on land in Ischia, not below the sea.

Now, each summer, Dr Alessandra Benini, the project's lead archaeologist - who has conducted self-funded excavations for the past 15 years - and her team excavate the sea floor. Due to the sea's seasonal turbulence, they are limited to working from May to October.

The discovery of a shipwreck in 2020 unearthed naval equipment, including a bronze mooring post in the shape of a swan's head, typical of Roman military vessels, as well as lead sling bullets, all of which suggest that Aenaria may have once been a crucial military outpost in the control of the Gulf of Naples. Since the initial digs, two seaside villas have been uncovered, with grand tunnel-like galleries, alcoves and traces of Roman baths.

"The ruins of Aenaria give insight into the lives of the ancient people who lived on the island," said local tour guide Marianna Polverino. "It was truly the centre of trade in the Mediterranean. You understand how important Ischia was - and still is - without ever forgetting the history that lies behind it."