The castle was built over the foundations of the Villa of Julius Caesar, which later became an imperial residence.
The defensive walls were engineered to withstand early gunpowder artillery, featuring thick, angled masonry.
The site contains the 'Ninfeo di Punta Epitaffio', a reconstructed Roman triclinium found underwater.
During the Bourbon period, the castle served as a military infirmary and later an orphanage.
The museum collection includes the cast of a statue of the Emperor Claudius.
The promontory is composed of 'yellow tuff', a volcanic rock typical of the Campi Flegrei geological area.
Archaeologists continue to study submerged ruins accessible via the museum's data and specialized glass-bottom boat excursions departing from the nearby port.
Castello Aragonese di Baia stands on a volcanic promontory overlooking the Gulf of Pozzuoli and houses the Archaeological Museum of the Phlegraean Fields. The fortress was constructed in the late 15th century by Alfonso II of Aragon on the site of a former Roman imperial villa. Its strategic position was designed to defend the coast against pirate raids. The museum exhibits artifacts recovered from the submerged Roman city of Baia, including statues and mosaics. The complex features multiple bastions, courtyards, and panoramic terraces offering views toward the islands of Procida and Ischia. Excavations within the fortress walls have revealed remains of luxury Roman living quarters. The site functions as a cultural hub for the Phlegraean Fields region, hosting rotating archaeological exhibitions. The architecture demonstrates significant military engineering developments from the Renaissance period.
The upper terrace near the main rampart offering a panoramic vista of the Gulf of Pozzuoli and the Mediterranean sea.
Wear comfortable, flat shoes as the site involves significant walking on uneven, sloped, and cobblestone paths.
Bring sun protection, as the ramparts have very limited shade during summer months.
Download the museum app before arriving, as cellular signal can be inconsistent inside the thick stone walls.
Do not attempt to walk to the castle from the Pozzuoli town center; it is physically disconnected and requires a separate transport method.
Closed on Mondays.
No flash photography in indoor museum sections; respectful behavior is required as it is a protected archaeological site.
