The Temple of the Magna Mater is situated at the west side of the Field of the Magna Mater. In front of the temple is a large masonry altar (opus reticulatum, decorated with marble). Here two honorary statues were once standing, of Publius Claudius Veratus Abascantianus and Publius Claudius Horatius Abascantianus. The statues were erected by their father, Publius Claudius Abascantianus, a high official in the guild of the dendrophori, the tree-bearers. One of the inscribed marble bases, with the consular date 194 AD, can still be seen near the temple. In the other inscription are the words in campo Matris Deum, "on the field of the mothers of the gods".
The temple has a podium of opus latericium with a cornice, and with three large niches in each of the sides and the back. It is noteworthy that the temple was smaller than the podium. The red bricks are Hadrianic, but they cover an older podium (opus reticulatum). At the front is a wide staircase, decorated with marble. It is interrupted by a landing, 2 meters deep. On each side of the landing a rectangular hole was found. Small pine-trees or flowers may have been planted here. Of the temple itself not much has been preserved (opus latericium, max. h. c. 0.70). According to Visconti there was an ante-room, preceding a cella with niches in the side walls (7.30 x 6.50). The cult statue may well be the statue of "Fortuna Annonaria" that today stands in the house of the same name: it seems to be a reworked statue of the seated Magna Mater. It would have been standing in front of a narrow base in the back of the cella.
Plan of the temple. From Vermaseren 1977, fig. 23.Many dedications by the guild of the cannophori, the reed-bearers, were found in the leftmost (northern) niche in the back wall of the podium, walled in. Presumably they had been hidden in late antiquity, out of fear that they would be destroyed by Christians or invaders. Nearby, behind the temple, dedications by the dendrophori were found. Several deities are mentioned: Magna Mater, Attis, Virtus, Silvanus, Numen domus Augusti, Genius decurionum Ostiensium. Some were made for the well-being of the Emperor. The seats of these two guilds must have been nearby, but have not yet been found or identified.
On the western part of the field several bronze and marble statues and statuettes were found on an unspecified location, of Magna Mater, Minerva, Mars, the Dioscures, Aesculapius, Diana, and also of Emperors.
