It has been preserved in an almost unaltered form, although the time of its erection dates back to the year 142 B.C. It is a small, round structure with an interior cell and a surrounding colonnade, consisting of nineteen slender columns finished with Corinthian capitols. Initially it was covered by a stone, semi-circular dome, in time it acquired its present-day roof. It was dedicated to a hero that was very important to the Romans – Hercules. The very same one, who as a mortal, thanks to his courage and strength was elevated to divine status. Romans took over his cult from the Greeks, for whom the victorious Heracles was an embodiment of heroism.

It is assumed that the original temple was dedicated to Hercules who had the nickname of Olivarius, which can easily be associated with the patron of olive merchants and olive oil producers. It was founded by a certain Marcus Octavius Herrenus, most likely a wealthy merchant who acquired his fortune dealing in the aforementioned products. When Julius Caesar himself recognized Hercules as his protector deity, the name of the temple was changed, dedicating it to Hercules Victor – the victorious demigod. Subsequent emperors also willingly identified with this hero.

Certain historians connect the imposing gilded statue of Heracles, presently found on Capitoline Hill (Musei Capitolini) with this very temple.

The cult of Hercules had been practiced in Rome since ancient times in the located nearby, unpreserved today, Great Altar of the Unconquered Hercules (Ara Maxima Herculis Invicti). The remains of this structure survived in the underground of the Basilica of Santa Maria in Cosmedin. On this very altar, in the times of the Republic (or perhaps even earlier) gifts and sacrifices were made prior to a planned, longer escapade or after returning from one, but the hero was also prayed to in order to ask for support before other important undertakings. The altar is also connected with great festivals organized on the day of the feast of the hero (12 August), during which the animals sacrificed on the altar were served. All the inhabitants of the city took part in these feasts.

The Temple of Hercules was only preserved thanks to the fact that in early Middle Ages its patron was changed. Initially this was a place of cult of the first Christian martyr – St. Stephen (Sanctus Stephanus Rotondus). It was not until the XVII century that the dedication of the church was changed to Santa Maria del Sole (Our Lady of the Sun), which was a reference to a miracle witnessed in a nearby house, during which a certain image of Our Lady shone with sunlight.

At the present, the square teeming with life is no longer located here, while tourists seldom come, at most to rest after seeing the nearby church, or more appropriately the Mouth of Truth found on the opposite side of the street. For some time now it has been possible on certain days to visit this buildings along with the nearby Temple of Portunus. Then, those who would like to immerse themselves in an atmosphere of an ancient city, have the opportunity to do just that. The best times to visit and enjoy a specific atmosphere are in the evening or at night, when even the buzz of cars is unable to destroy the aura of this place – old, but not intimidating, dignified but at the same time friendly. The complex of the two well-preserved temples as well as the nearby arches: Arch of Janus and Arch of the Silversmiths is a much better introduction into the aura of antiquity than even the ruins of Forum Romanum, where we can only imagine most of the buildings which had once been located there.