In 1827 Antonio Nibby reports finds in the area to the west of the Episcopium, near the bifurcation of the Fossa Traiana and the channel leading to the harbour basins. Translated from the Italian:
From modern Porto going for a small stretch along the new road to Fiumicino, just before passing the canal between the harbour and the river, an irregular area paved with enormous blocks of porta santa, affricano, and cipollino was discovered on the left in the present year, the beginning of a road and a small portico of columns. In 1858 Charles Texier regards this area as the Forum of Portus. Translated from the French:
I was not, however, discouraged by the sight of the overturned earth in the Forum, and I had a wide trench opened; it did not last long until I uncovered, at a depth of 1 m., a marble floor of great richness; all blocks were placed without colour distinction; one recognizes the cipolino, the African marble, the Greek marble and the antique green (Porto-Santo); the blocks have a length of 1 m. 50 cm. to 2 m., and their thickness is more than 0 m. 70 cm. to 1 m. There is no further indication that there was a Forum here. More likely were are dealing with a marble yard. Another such yard has been located on the opposite side of the Fossa, on the Isola Sacra.
In 1868 Rodolfo Lanciani discusses the same area and speaks of "that small area discovered in 1827 around an unidentified temple, whose floor is described by Nibby". A small rectangular temple can be seen on his plan. It is not clear at all however whether it was actually found. Lanciani (like Giuseppe Lugli, writing in 1935) may well have been inspired by the depiction of a Temple of Apollo on a copy of an ancient, lost painting. The painting has been regarded as a depiction of Portus, but it is more likely that we see Puteoli or an idealized view of a port.
The plan of the area by Rodolfo Lanciani.Françoise Van Haeperen has suggested that there may have been a temple of Serapis in this area, because all inscriptions referring to the deity for which we have more or less precise information have been found between the basin of Trajan and the Fossa Traiana, or were reused in the Basilica of Saint Hippolytus, a bit to the south, on the Isola Sacra.
Sources
Nibby 1827, 91; Texier 1858, 53-54; Lanciani 1868, 193; Lugli-Filibeck 1935, 105-106; Keay et al. 2005, 47; Van Haeperen 2019, s.v. "Portus. Temple anonyme, à proximité de l'Episcopio", and s.v. "Portus. Temple de Sérapis (localisation incertaine)".
