The Temple of Heracles has been attributed to the divine hero Heracles on the basis of a plausible testimony by Cicero.
It is the most ancient temple in Agrigento, as its origin dates back to the end of the 6th century B.C.
The building, in local calcarenite stone, is Doric in style and rests upon a base (crepidoma) with three steps; it has six columns at the front and back and fifteen along the sides.
The interior of the temple was divided into three rooms: the central room called cella (or naos) was preceded by a porch (pronaos) and followed by a room at the rear (opisthodomos); both the pronaos and the opisthodomos had two columns in front.
At the sides of the entrance to the cella, there were two stairways to the roof, which was decorated by drips for rain water, shaped as lion heads.
To the east of the temple are the remains of a monumental altar.
During the Roman period the cella was divided into three parts, probably because the cult of Heracles was associated to that of other two divinities.
One of these could have been Asclepius, a statue of which was found in the modified cella Numerous restorations have taken place since 1921, when, as a result of the initiative of the English captain Alexander Hardcastle, eight columns were re-erected on the southern side of the temple.
More recent interventions by the Park Authority, with European Union funds (POR Sicilia 2000-2006), have been aimed at the conservation of the building.