This temple was erroneously attributed to Juno (Hera) due to the incorrect interpretation of a text of a Latin author.
It is built in local calcarenite stone and is erected in a dominating position, on the eastern extremity of the Collina dei Templi ('Hill of the Temples').
The temple in Doric style (450-440 B.C.) rests upon a base (crepidoma) with four steps and has six columns at the front and back, and thirteen along the sides.
The interior was divided into three rooms: the central one called cella was preceded by a porch (pronaos) and followed by a room at the rear (opisthodomos); both the pronaos and opisthodomos had two columns in front.
On the side walls of the cella there were stairs leading to the roof.
The base with three steps below the cella is a later addition. Some stone blocks are reddened, which is probably evidence of the destruction of Akragas by the Carthaginians, who set fire to the city in 406 B.C.
On the eastern side of the temple are the remains of the monumental altar preceded by ten steps, which led to the level where the sacrifices took place.
The temple has been subject to many restorations starting in the 18th century, when the columns of the northern side were re-erected.
The last interventions have been undertaken under the aegis of the Park Authority with European Union funding (POR Sicilia 2000-2006) and have been aimed at securing the static stability of the building and at restoring its stone blocks.
West of the temple is the Third Gate, only a few ruins of which survive to this day due to a landslide.
The gate used to open obliquely to the line of the fortifications and was crossed by a carriageway, which is still visible.
The defensive system, dating back to the 6th century B.C., was reinforced in the 4th century B.C. by the construction of a large tower, which survives in the form of collapsed rubble to the north-east of the gate and of the temple.