This elegant building of the lonic order is called, according later literary sources, Erechtheion from the name of Erechtheus, the mythical king of Athens. The construction started before the outbreak of the Peloponnesian War (431 B.C.) or after the conclusion of the “peace of Nikias” (421 B.C.) and was finished in 406 B.C., after the interruption of the works because of the war.
The peculiar plan of the building is due to the natural irregularity of the ground and the need to house the ancient sacred spots: the salt spring, which appeared when Poseidon struck the rock with his trident during the contest with Athena over the patronage of the city, the trident marks and the tombs of the Athenian kings Kekrops and Erechtheus.
The Erechtheion consists of a rectangular cell divided by an interior wall forming two sections. The eastern section, which was at a level at least 3 m. higher than that of the western, was dedicated to Athena Polias and housed the xoanon, the ancient wooden cult statue of the goddess. The western section was divided into three parts and was dedicated to the cult of Poseidon-Erechtheus, Hephaistus and the hero Boutes.