In the 1st century AD the so-called "Temple of Diana" would be the main element of the Roman Forum. It is one of the best preserved in the Iberian Peninsula. Its wrong name is due to Father Manuel Fialho who in the century. XVIII when studying the building, gave it the name of Temple of Diana. The configuration of the temple corresponds to the Greco-Roman architectural system of the Corinthian order, hexastil, temples generally intended for official services.

Built at the dominant point of the Acropolis of Évora, of which it would be the main decorative element, possibly in the first decades of the 3rd century AD, when the cultural influences of Emperors Trajan and Hadrian extended across the Peninsula, however it is unknown what divinity it was dedicated to and what is the exact period of destruction, which everything seems to indicate was intentional, at the end of the 4th century or 1st half of the 5th century, the most intense period of religious persecutions against paganism. Diana's poster designation belongs to an erudite, 17th century version, attributed to Jesuit Manuel Fialho, in Evora Ilustrada. Transformed into public butchers in the reign of D. Afonso IV, walled and draped with gothic battlements, he was freed from the adventitious elements in 1871, at the request of the director of the Public Library DR. Augusto Filipe Simões, Mnauel Viana, Alexandre Herculano and Cinatti, who directed the restoration. The rectangular temple, of the Corinthian style and hexastil-peripteral type, is based on both soles of opus incertum, from where a colonnade of Greek-Roman stems breaks, which still preserves part of the architrave and frieze. The building whose pediment was directed to the southern side, is made of granite, except for the capitals and bases, which are made of Estremoz marble. The cell has completely disappeared.