Οι μετόπες είναι οι ορθογώνιες πλάκες που εναλλάσσονται με τρίγλυφα στο διάζωμα του ναού πάνω από τα επιστύλια. Ήταν τα πρώτα τμήματα του ναού που διακοσμήθηκαν με ανάγλυφες μυθολογικές παραστάσεις από σπουδαίους γλύπτες της εποχής (445-440 π.Χ.). Oι 92 μετόπες του Παρθενώνα εικονίζουν:
α) στην ανατολική πλευρά την Γιγαντομαχία, δηλαδή τον αγώνα των Ολυμπίων θεών με τους Γίγαντες που ήθελαν να ανατρέψουν την τάξη του Ολύμπου,
β) στη δυτική πλευρά την Αμαζονομαχία, τον αγώνα των προϊστορικών κατοίκων της Αθήνας, εναντίον των Αμαζόνων που είχαν εισβάλει στον τόπο τους,
γ) στη νότια πλευρά την Κενταυρομαχία, την άγρια πάλη ανάμεσα στους Κενταύρους και τους Λαπίθες, λαό της Θεσσαλίας, γιατί οι πρώτοι θέλησαν να αρπάξουν τις γυναίκες των Λαπιθών κατά την τελετή του γάμου του βασιλιά τους Πειρίθου, τέλος
δ) στη βόρεια πλευρά σκηνές από τον Τρωικό πόλεμο.
The frieze or diazoma of the Doric temple, which encircles the entire building between the architrave and the overlying cornice, is comprised of alternating triglyphs and metopes. On the Parthenon, all the metopes are decorated with sculpture, an arrangement that is unique in ancient Greek architecture.Their relief is so high that if the temple were to be viewed directly from that height the triglyphs would not be discernible and the relief would appear to be continuous.
The ninety-two metopes were the first of the sculptural decoration to be made for the temple. They were carved on the ground by different teams of sculptors and stone-cutters, who undertook the work in separate teams. Among them were also metics, (resident aliens) who had come to Athens mainly from the Aegean islands. This explains the slight differences of style in the metopes.
The themes of the reliefs in the metopes are drawn from Greek mythology. Most, indeed, depict a favorite subject in ancient Greek art, the contest.
Visible on the east side, the most important view of the great temple, were scenes from the Gigantomachy, the mythical battle between the gods of Olympos and the Giants, who tried to upset the order of the world.
At the other end, at the west, were scenes of the Amazonomachy. The Greeks, with their hero Theseus, confronted the Amazons, a barbarian tribe of female warriors who according to myth lived somewhere in the Pontos, (in the region of the Black Sea).
Depicted on the north side were scenes from the Trojan War, mainly the conquest and destruction of Troy by the Achaean Greeks, a theme known as the Ilioupersis.
On the south side, twenty-three metopes are devoted to the Centauromachy, while the other nine, in the middle, have yet another subject. The Thessalian Lapiths invited their neighbors the Centaurs to the wedding of their king Peirithoös. The Centaurs, so says the myth, were a barbaric tribe with the body of a horse and the torso and head of a man. At the wedding the Centaurs became drunk and tried to make off with the Lapith women, so that a hand to hand battle ensued. For the Greeks, the Centauromachy signified the confrontation of civilisation and logic with barbarity.
Thus on the metopes of the Parthenon there are four main themes that are known from the sculpture of many other Greek temples as well as from various other works of art. The themes are connected with the Contest, the Struggle, between two adversaries, whoever they may be. This expression of the Contest is unsurpassed and stands as a symbol of the eternal fight between the opposing and counterpoised forces in nature, in human society and in the human soul. In essence the Struggle is indecisive and is therefore without end. The outcome itself is thus of little importance compared to the process. The deep meaning of the work bespeaks the maturity of the society that created it and its intellectual distance from the art of its neighbours in which the closest theme is concerned solely with a struggle always won, and with the humbling of the defeated enemy.