At Vasi's time this large circular building was thought to be a temple to Hercules built by Decimus Junius Brutus, a Roman general who in 137 BC conquered the Spanish region known today as Galicia. The Roman Senate granted him the title of Callaicus. The building was also known as Tempio di Minerva Medica after a statue which was found there at the beginning of the XVIIth century (but today art historians believe it was found elsewhere, perhaps at Campo dei Fiori): it portrayed the goddess with a snake, a symbol of Medicine. It is known as Athena Giustiniani
because it was part of the Giustiniani collection.
The small 1748 map here below shows 1) Tempio di Minerva Medica; 2) S. Bibiana.
The view in May 2009
The ruins are now imprisoned between a tramway leading to Porta Maggiore and the rail track leading to Stazione Termini and yet they still call for admiration. The vault partially collapsed in 1828. The building was not a temple, but a IVth century AD nymphaeum, a monumental fountain.
View of the side where the vault collapsed
The drum has the shape of a decagon and it supports a concrete dome having a diameter of 25m/82ft, the largest one of ancient Rome after those of the Pantheon and of a hall of Terme di Caracalla. The image used as background for this page shows arches supporting the dome.
(left) Centrale Montemartini: three statues found in 1887 inside the nymphaeum: they portray (left to right): Dionysus, a satyr and a seated maiden; (right) Museo Nazionale Romano: head of Emperor Hadrian found near the nymphaeum
The nymphaeum stands on the area of Horti Liciniani, a large
villa belonging to the Licini, the family of Emperor Licinius Gallienus (260-68).
Whenever he (Gallienus) went to the gardens named after him, all the staff of the Palace followed him. And there went with him, too, the prefects and the chiefs of all the staffs, and they were invited to his banquets and bathed in the pools along with the prince. Women, too, were often sent in, beautiful girls with the emperor, but with the others ugly old hags.
Historia Augusta - Volume III - translation by David Magie - Loeb Classical Library.
The statues found inside the nymphaeum were made at the time of Emperor Hadrian, more than a century before Gallienus rose to power and almost two centuries before the construction of the nymphaeum itself. They perhaps belonged to a previous wealthy owner of the gardens.
Centrale Montemartini: mosaic found in the area of Horti Liciniani and details showing a boar hunting scene
A large mosaic was found in 1904 in the proximity of the nymphaeum. It is the same age as the building and it indicates that Horti Liciniani continued to belong to a very wealthy family after the son and the relatives of Gallienus were all killed in 268.
Centrale Montemartini: other details of the mosaic
The style of the mosaic departs from traditional patterns as it lacks an elaborate frame and the figures are depicted against a white background. The hunters all wear heavy clothes which is another remarkable deviation from tradition. Some details recall scenes of a large mosaic of the palace of Emperor Justinian at Constantinople.
Excerpts from Giuseppe Vasi 1761 Itinerary related to this page:
E' questo di figura rotonda fatto di mattoni, rovinato solamente verso levante: alcuni perņ lo credono di Ercole Callaico eretto da Giunio Bruto per aver soggiogato i Callaici popoli della Spagna.