The archaeological park area contains impressive ruins of thermal and hydraulic structures, the ‘Cento Camerelle’, the ‘Piscina Mirabilis’, the Tomb of Agrippina, the military port of Miseno, the theatre, and various monumental tombs: it is an archaeological legacy without equal. Baiae was the quintessential Phlegraean residential resort, patronised by the most eminent Roman figures and the chosen destination of the imperial family itself on account of its salubrious climate and the therapeutic properties of its waters. The most prominent proof of this use of the town is the vast and complex architectural structure of the so-called ‘Thermae’, in which it is possible to recognise what are probably the remains of the imperial Palatium. This complex – in which various groups of buildings and diverse phases of construction can be distinguished – unfolds in a spectacular manner along the slope of the hill in a series of terraces, flights of steps, colonnades, and nymphaea, adopting bold architectural solutions, as in the Thermae of Sosandra and in the three rooms referred to by Neapolitan antiquarian literature as the ‘Temple of Diana’, the ‘Temple of Mercury’ and the ‘Temple of Venus’. In addition to the complex, which – as recent underwater surveys have demonstrated – once also occupied the area that is now submerged as the result of the phenomenon of bradyseism, visitors can also access the adjacent monumental park, which, established in 1980 as an equipped green space, encloses numerous structures that have not yet been systematically explored, but pertain without doubt to the above-mentioned complex, whose original nucleus, identified as the villa of Julius Caesar, has recently been brought to light. The majority of Baia’s fabulous buildings are submerged by the sea; these ruins form the Parco Archeologico Sommerso di Baia. Thanks to excursions on specially adapted boats and to underwater film footage, mosaic floors, walls, columns, and other remains can be seen. The submerged ruins of the Nymphaeum of Punta Epitaffio are also part of an imperial residence. The statuary from this grotto, dating to the Julio-Claudian Age, has recently been reconstructed and exhibited at the Museo Archeologico dei Campi Flegrei, which was set up in 1994 inside the restored Castello Aragonese. In nearby Bacoli, known in antiquity as Bauli, it is still possible to see a mighty underground cistern dating back to the 1st century B.C. known as the ‘Cento Camerelle’, and the atmospheric ruin dubbed the ‘Tomb of Agrippina’, which in actual fact is a theatre-nymphaeum belonging to another imperial residence.