Discover Baia: the Castello and the sunken Roman city
Accommodation in Baia
Baia offers two distinct archaeological perspectives: the ancient Roman coastal city sank below sea level, while the Castello Aragonese was built toward the end of the 15th century as part of a fortification program. For your travel planning, this means that the underwater sites and the castle explore different historical themes. The travel information also covers different routes.
The sunken coastal city and its sites
The Parco sommerso di Baia is a protected marine area in the Gulf of Pozzuoli. In the Parco Archeologico Sommerso di Baia, Roman villas, thermal complexes, roads, and harbors are preserved across 180 hectares and at depths of 4 to 8 meters. The focus is therefore not on a single structure, but on a vast archaeological heritage with a range of features.
Due to bradyseism, the ancient Roman coastal city of Baia sank below sea level. Mosaics, statues, columns, and architectural structures were preserved a few meters beneath the sea’s surface. These surviving structures make the connection between the city’s history and geological change the central theme of the underwater area.
Since 2001, the sites have been made accessible through guided scuba dives, snorkeling tours, glass-bottom boat excursions, and a small tourist submarine. These options range from diving and snorkeling activities to trips by boat or submarine. Before your trip, check which options are currently available.
Castello Aragonese and the archaeological museum
The Castello Aragonese di Baia was built toward the end of the 15th century as part of the fortification program promoted by the Aragonese dynasty in the Kingdom of Naples. The complex stands on the remains of Roman residential structures and houses the Museo Archeologico dei Campi Flegrei. The Castello thus brings together traces of Roman residences and a later fortification.
The museum collects and displays archaeological finds from Baia, Cuma, Puteoli, and Liternum. Its holdings include plaster casts from Baia, considered a unique testament to Hellenistic and Roman casting techniques. According to current knowledge, the “Mercurio” area contains the oldest known example of a large-scale hemispherical concrete dome. The “Mercurio” hall has been dated to the time of Augustus.
A visit to the Castello takes you through various parts of the complex, which are some distance apart, and leads to Piazza d’Armi. From there, you can enjoy panoramic views across the entire Gulf of Naples. The route through the castle and the view from Piazza d’Armi complement the archaeological focus with architecture and scenery.
Getting there and finding your way
From Napoli Montesanto, you can take the EAV Ferrovia Cumana to Fusaro or Lucrino. From there, you can take an EAV bus or walk about one kilometer. As transport information can change, check the latest information from EAV before setting out.
Intercity EAV buses to the Castello run from Fuorigrotta or from Piazza Garibaldi or Porta Nolana to the Baia – Via Castello stop. From there, it is just a short walk to the entrance of the Castello Aragonese di Baia. The two route descriptions offer different starting points and options: one via the Cumana and one by bus to the stop by the Castello.
If you are choosing between the archaeological themes, the sea and the castle offer different perspectives on Baia: underwater, the focus is on Roman urban structures and ways to access them; at the Castello, it is on the fortification, the museum, and the panoramic views. These differences can help you shape your stay around your interests in underwater archaeology, museum collections, or architecture.
Discover more destinations: Poggiomarino, Santa Maria La CaritĂ , Mariglianella, Somma Vesuviana, Melito Di Napoli, Tufino, Qualiano, Marigliano.
For the broader travel overview: Naples.
