At the end of the Archaic period an imposing temple was constructed in the position of the Classical one seen today, but it was slightly smaller in dimensions. It was Doric, made of poros, with an external colonnade of 6 x 13 columns, and an internal one which supported the roof. Its construction was interrupted by the Persian invasion and the temple remained unfinished. The later temple, the one preserved today, was also Doric, with 6 x 13 columns, made of Agrileza marble, but without an internal colonnade. The stylobate measured 13,47 x 31,12 m. It was constructed in 450-440 B.C. and, according to another theory, was the work of the architect who had also built the Hephaisteion ("Theseion") in the Ancient Agora of Athens, the Temple of Nemesis at Rhamnous, and the Temple of Ares which was probably erected in Acharnes. The sculptural decoration of the temple, made of Parian marble, is preserved in a poor condition. The frieze of the east side depicted Centauromachy, and the east pediment (of which only a seated female figure is preserved) probably depicted the fight between Poseidon and Athena for the domination of Attica. The two antae of the east side and several of the columns of the east part of the temple are still preserved today, while the west is completely destroyed.