Only a careful  study of the greatly disarranged ruins of its elements can permit us to state that the temple A, built around the middle of the V Century B.C., was the most harmoniuos and perfect classical temple of Selinunte. However, a sensitive eye can appreciate the classic beauty of the precise forms of the architectonic structures, and especially of the capitals, in spite of their advanced state of corrosion.
In the overall moderate size temple (stylobate 16.23 x 40.24 m), thc columns placed in a ratio of 6/14, which was by now canonical for Greek western temples, and with standard interaxes of equal size both on the facade and on the sides, enclose the cella in perfect syinmetry.
In order to solve the problem of the comer of the Doric architectonic order of the classical era, which was due to the fact that at the comer the triglyphs cannot coincide axially, with their respective colunms, the interaxes of the columns nearest to the coner gradually contract.
Furthermoore, the columns were i slightly inclined towards the interior of the temple in order to even out the remaining small differences and to be able to give, at the end., a perfectly regular form to the frieze of triglyphs and metopes. This intentional slight inclination, a contrivance that was well known in the classical temples of Greece itsetf, -and here, only observed with precise measuring-, greatly contributes to rendering plastic and compact the volume of the entire; temple and it is a further clue to the high architectural-artistic level of this noble monunent. A sima, richly decorated in precious marble from the Greek island, crowned the well-proportioned elevation.
In the cella, the pronaos, the eastern entrance hall with two columns in antis is counter-balanced to the west by the analogous rear porch, the opisthodoinos. The adyton is separated from the naos, the fomer being the room for the cult statue thet seems to be fundamental in Selinunte. This leads to the unusually ghonened, but exactly for this reason veiy harmonious, proportions of the main hall.
A particularly elaborate element are the two spiral staircases in the entrance wall to the naos, a contrivance that can only be explained by the requirements of the cult which howevr still remain obscure. This is the first example ofi spiral staircase in the entire history of architecture.
The temple created an architectural unity with its huge altar vhich, in its turn, is the most complex example of this type in the classical age. In fact the altar itself is a small portrayal of all the forms of the large peripteral ternple. The table of the altar was enclosed by a colonnade with a complete Doric entablature; the whole structure rose from the relative steps and two whole pediments acted as sides to the altar.
Only the side that faced the temple was interrupted by the wide staircase that was necessary for the cult functions.

Sull'acropoli sorgono  il Tempio A ed il Tempio O: il primo è un periptero esastilo di 40,23 X 16,23 metri ed aveva due scalette circolari fra il pronao e la cella (sopraelevata di un gradino rispetto al pronao) che portavano sul tetto. Sul pavimento del pronao sono stati ritrovati i segni di Tanit, del caduceo ed una testa di toro circondata da foglie di alloro .
Ad est sono stati rinvenuti i resti di un edificio con pianta a T, forse un'ara o i propilei del tempio. Infine, il tempio O, situato a nord del tempio A, molto simile ad esso.