It was erected by Vespasiano in 73 A.D., as evidenced by the inscription on the pediment. The area was occupied on three sides by a terrace with at the centre the temple and two wings on either side of the portico to the Forum. The staircase leading to the podium of the upper vestibule, with a central structure and six Corinthian columns of about 11 metres. The temple has three rooms separated by cavity walls: large doors lead to the prison cells, which exhibit inscriptions, tombstones and sculptures. The floors made of well-preserved marble slabs are also noteworthy. The temple closed to the north the Forum and it was connected to the decumanus by a central staircase between sections of wall with blind arches. Traces of dwellings, burials and production facilities of the Lombard era are still present in the archaeological site of monuments, which is why the archaeological site is included in the UNESCO World Heritage List, together with the complex of San Salvatore-Santa Giulia.