<P> The Temple of Hercules Victor (' Hercules the Winner') (Italian: Tempio di Ercole Vincitore) or Hercules Olivarius is a Roman temple in Piazza Bocca della Verità, in the area of the Forum Boarium close to the Tiber in Rome . It is a tholos - a round temple of Greek' peripteral' design completely encircled by a colonnade . 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 . 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 . </P> <P> Dating from the later 2nd century BC, and perhaps erected by L. Mummius Achaicus, conqueror of the Achaeans and destroyer of Corinth, 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 . These elements supported an architrave and roof, which have disappeared . The original wall of the cella, built of travertine and marble blocks, and nineteen of the originally twenty columns remain but the current tile roof was added later . Palladio's published reconstruction suggested a dome, though this was apparently erroneous . The temple is the earliest surviving marble building in Rome . </P> <P> Its major literary sources are two almost identical passages, one in Servius' commentary on the Aeneid (viii. 363) and the other in Macrobius' Saturnalia . Though Servius mentions that aedes duae sunt, "there are two sacred temples", the earliest Roman calendars mention but one festival, on 13 August, to Hercules Victor and Hercules Invictus interchangeably . </P>

When was the temple of hercules victor built