This layout caused it to be mistaken for a temple of Vesta until it was correctly identified by Napoleon's Prefect of Rome, Camille de Tournon.

[2] Despite (or perhaps due to) the Forum Boarium's role as the cattle market for ancient Rome, the Temple of Hercules is the subject of a folk belief claiming that neither flies nor dogs will enter the holy place.

[4] Dating from the later 2nd century BC and erected by L. Mummius Achaicus, conqueror of the Achaeans and destroyer of Corinth,[5] or by Marcus Octavius Herrenus,[6] the temple is 14.8 m in diameter and consists of a circular cella within a concentric ring of twenty Corinthian columns 10.66 m tall, resting on a tuff foundation.

The temple's original dedication is dated back to circa 143-132 BC, a time when intense construction was taking place in Portus Tiberinus.

[11] In the 1st century AD, the temple was hit with some sort of disaster as 10 columns were replaced with Luna marble, which is similar to the original but not an exact replica.