The Bar of Fortunatus was excavated in 1909 by Dante Vaglieri. It was installed in a room that was originally a passage between the Decumanus to the south and Via della Fontana to the north. A new passage between the roads was created to the east of the bar. There is a wide entrance in the south wall of the bar, with a travertine threshold that has a groove for the insertion of wooden shutters and a depression for a door. A door in the east wall leads to the new passage. A wide entrance in the north wall was blocked. In the west wall are a blocked doorway and a small window. The room measures 6 x 4.60 metres.

On the floor is a black-and-white mosaic with a drinking vessel and the damaged inscription:

It is interpreted by Vaglieri as follows:

A variant has been proposed by Guido Calza: (dicit) FORTVNATVS (vinum cr)ATERA QVOD SITIS BIBE. Ashby interprets Fortunatus as a nominative for a vocative, and takes cratera as the Greek form of the accusative, translating: "Fortunatus, drink the bowl, because you are thirsty". He does not, however, take the missing letters to the left into account. Becatti dates the mosaic to the first half of the third century AD.

The room has been identified as a bar on the basis of the inscription and the depiction of a crater, taken together with the shop-threshold in the south entrance. A bar counter has not been preserved. Possibly nymphaeum II,VI,2 and three more rooms, to the west, belonged to the bar.

It is a bit strange that the inviting text was read from the east, by people standing next to a narrow door, in front of a wall, and not from the wide entrance in the south wall. Also, the word "because" instead of "when" or "if" is a bit surprising. The text brings to mind a few words spoken by Jesus (John, 7:37-38): In novissimo autem die magno festivitatis stabat Iesus et clamabat dicens si quis sitit veniat ad me et bibat. Qui credit in me sicut dixit scriptura flumina de ventre eius fluent aquae vivae ("And on the last, and great day of the festivity, Jesus stood and cried, saying: If any man thirst, let him come to me and drink. He that believeth in me, as the scripture saith: Out of his belly shall flow rivers of living water"). The text was found as a graffito in the Catacombs of Priscilla in Rome, on the arch of the baptistery: QUI SITET VEN(iat ad me et bibat). In the words of Lanciani it is "an allusion to the regenerating powers of the water, which occurs in other baptisteries of the post-Constantinian age". The bar is located next to an area where Christian martyrs were executed (see the Christian Oratory (II,VII,1)).