In 1931-1932, during the reconstruction of a mill into the warehouse of the Teatro dell’Opera, a large sized, almost perfectly preserved Roman building-complex was discovered under the building. Because the warehouse is not accesible for the greater public, the sanctuary can be rarely visited, only through a touristic association. They are former students and archaeologists, well prepared in Roman history and classical archaeology and also in local topography of the finds – a necessity in such a city, as Rome, where every serious archaeologist should know by hearth the archaeological guide of Coarelli at least.

The sanctuary is preserved in a stunning state, almost perfectly: arches, vaults, pavimentum, the marble decoration of the walls, porphyr objects are in situ in the sanctuary. Even some parts of the original wall paintings and decorations are visible, however these seems to be heavily damaged in the last 80 years.

The building was part of the Forum Boarium and the area of the Ara Maxima Herculis Invicti, the big central altar of Hercules, which is partially preserved under the church of Santa Maria in Cosmedin. The Ara Herculis was rebuilt after 64 AD, so what it might be preserved under the Cosmedin is actually the new, Principate-period building and not the Republican altar. In any case, this area was one of the central sacralised spaces of Rome with high significance, especially for men. This might be a good reason to establish a mithraeum here, although the building where they identified it originally was a horreum or a similar, economic structure (something similar was found also in the port of Caesarea Maritima).

The original building was transformed in the period of Diocletian, additional walls were added, to create the three major area of the sanctuary: the pronaos, the apparatorium and the naos, the central nave with podia. The marble decoration, the spheres on the pavimentum and the rich ex voto decorations, statues and statue bases are dated also from the end of the 3rd beginning of the 4th century.

The central relief now is lying on the left bench of the naos, originally was found in the central area of the sanctuary. It represents the canonical, classic tauroctony, with stars near the head of Mithras. Another, ex voto relief is still in its original position inserted in the wall of the sanctuary. Several other niches suggest, that the walls of naos were heavily decorated with inscriptions and reliefs. Some of the inscriptions are on the walls of the pronaos, probably put there by archeologists. Another important inscription is walled in one of the statue bases near the central area. This might suggest, that in the 4th century the building was again, reused and left by the Mithraic group. Several, badly preserved graffiti can be observed on the wall. As far as I know, this was never been studied with contemporary technologies. The case of the Caesarea Maritima mithraeum shows, that with infrared and other laser technologies, badly preserved graffiti and frescos can be identified. I’m almost sure, that would be the case in this amazing mithraeum too. One of the most discussed graffito of the sanctuary is the one which mentions the word of “magicae” (CIMRM 454). Guarducci and H. Solin wrote also some important works on this topic.

The sanctuary was published in several short reports and articles in the 1930’s by Pietrangeli, Colini, Luigi and others. Later, M. J. Vermaseren had a long entry in his monumental corpus about the sanctuary and its inscriptions too (CIMRM 434).

Vermaseren collected all the material he could from A.M. Colini and the few reports existed in the 1950’s when he wrote his entry for CIMRM. It is clear from the epigraphic material, that many of the inscriptions are from the 2nd century AD, which is in a slight conflict with the pavimentum, which clearly suggest, that it was built in its recently known form during Diocletian’s period. The mithraeum might have therefore at least two phases: a Hadrianic one and a later, 3rd century one. It could be also, that a Mithraic group moved from an older sanctuary into this new one, moving the old inscriptions (CIMRM 449, 453) with them. One of the inscriptions (CIMRM 449) mentions, that the sacrarium (the mithraeum?) was built by Publius Aelius Ur(banus?), when A. Sergio Eutycho was sacerdotes, priest (of Mithras?). The name of Ur(banus?) suggest, that we are in the period of Hadrian or post-Hadrian. None of the early publishers of the sanctuary named this mithraeum as “mitreo di Circo Massimo”. The building was at least 20 m distance from the Circus Maximus, separated by a Roman road from the edges of the circus. It is clearly not part of the monumental structure, but a separate building, part of the economic area of the Forum Boarium and the sacralised spaces of the Ara Herculis. Still, since the 1970’s Italian and later, English literature cites this sanctuary as the “mithraeum from the Circus Maximus”, which is very misleading.

The sanctuary of Publius Aelius Ur(banus) or Sergio Eutycho could be more authentic denomination. The sanctuary would worth a monograph too.

Some photos from the interior of the sanctuary: