Between the years of 1936 and 1937, an underground environment was discovered at the Boario Forum. The ancient site constructed in squared blocks of volcanic rock, was composed of two cells, with two large altars made of peperino, sacred wells, and a complex, multi-layered flooring. Found under the apse of the church of St. Omobono, the ruins of an archaic temple were discovered. Especially important, this temple is the oldest known example of the type built by tuscans in a roman environment. The oldest phases of building can be dated in the mid 6^th c. BC and the decoration toward the end of the 6^th c. BC. The first temple on the site was probably destroyed by a fire and reconstructed in the second half of the 6^th c. BC, with the addition of a contropodio. The majority of the work in terracotta and the facing of the stone slabs were probably added during this phase of construction.

The site was dedicated to the Mater Matuta, as indicated by the tributes to her found among the decorations in the temple. According to the mythological account, Leucotea, a goddess of Thebes, landed with her son Portunus on the banks of the Tiber. She assumed the name Mater Matuta and is known as the protector of navigation.

At the end of the 6^th c. BC, the temple of Mater Matuta was destroyed following the expulsion of the Tarquins from Rome. Reconstructed at the beginning of the 5^th c. BC, two temples were combined; the western one was dedicated to Fortuna, and the eastern one to Mater Matuta. These two temples were demolished by fire 212 BC and rebuilt at the end of the 3^rd c. BC. In the 6^th c. AD, a paleo-christian church was installed in the pagan temple. The church was restored in the 12^th-13^th c. and given a new pavement in the Cosmati style. In 1482, the church was once again remodeled and renamed S. Salvatore in Porticu, which it remained until 1700 when it was finally dedicated to Sts. Omobono and Antonio. The church was most recently restored and re-floored in 1940.