Ionic dipteral temple built during the tyranny of Polycrates (538-522 B.C.).
Only one column is still standing today, preserved up to half of its original height, while the foundations are preserved up to the base of the walls and the stylobate.
Herodotus considered this temple as the largest in Greece. It follows almost exactly the contour lines of the cella and the pronaos of the older temple "of Rhoikos" (570/60 B.C.), but it is much larger (108.63 x 55.16 m.). This difference in size is due to the addition of a third colonnade to the front and back of the peristasis, apparently following the example of the temple of Artemis at Ephesus, which had been built slightly earlier. The temple had a total of 155 columns, belonging to four different sizes and types. The entablature must have been made of wood. Since no tiles were found, it is suggested that the roof was never completed.