The Submerged Park of Baia is an archeological reality of immense value that the bradyseism has confined on the seabed. The sea, resource which enables the beauty of Campi Flegrei, blends with archeology: underneath a thin layer of sand numerous mosaics are discovered and the wildlife animates remains of walls and statues. A large ancient shoreline was firstly covered by the sea. This shoreline should be imagined as continuity of the structures on land that are now part of the Archaeological Park of therms and that overlooked a much more narrow bay than the one we know now, anciently named “Baianus Iacus”, and that was accessible through an artificial canal. The inlet was already occupied by seaside villas during the republican age. Among the main structures visible, there is the “ninfeo” dating back to the claudian age, which is situated at minus 7 meters on the seabed opposite to Punta Epitaffio. Meanwhile, to the east of the nymphaeum there is a villa attributed to the Pisoni family for the boluses impressed on a lead water pipe. Other villas and therms occupied the large area around the now submerged lacus: among these, the villa with the entrance to the porch, should definitely be mentioned. This villa is now one of the most visited by divers and snorkelers.