Baths of the Blue Nymphaeum
Indeed at the foot of this church, spread out over several terraces which run down the slope of the hill, a thermal complex was discovered in the 1980s. The baths where probably part of the Roman villa depicted in the fresco. The remains that were found seem to point to various phases of the complex, dating from the second century BC until the 472 AD eruption of Vesuvius when the complex was abandoned.
While visiting the site, one can easily recognise the typical layout of a thermae; at least three rooms were for hot baths (calidaria), one of which seems to have served as a sauna (laconicum), and one additional room for taking a cold bath (frigidarium) in a covered pool (natatio) that was originally decorated with marble slabs.
The heating system used for the hot baths is still visible. During use, the hollow space beneath the pavement was filled with heated air (hypocaustum) with the water supplying the system connected to a nearby cistern (caput aquae).
On one of the lower terraces there is a beautiful nymphaeum from the Tiberian age that contains an apsidal fountain with a basin and a small shrine along its outer edges. The shrine marks the beginning of a series of niches whose walls were decorated with mosaics of blue and white tesserae. In many places the mosaic is lost, which may have occurred before the eruption of AD 472. The mosaic that survives show scenes of extraordinarily detailed beauty such as vases with plant life, still nature with parrots and scenes of deer hunting.
The room facing the nymphaeum may have been used for banquets (triclinium) in its first stage. Several centuries later it was converted into a space for oil production, with two grindstones and a press, until the eruption of Vesuvius.