The Erechtheion, a composite marble Ionic building, considered the most sacred site of the Acropolis. The eastern part of the temple was dedicated to Athena-Polias, protector of Athens and the western to Poseidon - Erechtheus from which it took its name. 

In mythology, the site of the Erechtheion was the place of the contest between Athena and Poseidon over the name of the city. The sea god Poseidon struck a rock with his trident and caused a spring of salt water to gush forth from the ground. In turn Athena struck the ground with her spear and an olive tree grew. The gods who were the judges announced Athena as the winner but the Athenians wishing to reconcile the two rival gods dedicated a shrine to both of them under the same roof.

One side of the temple was decorated wit six Ionic columns while the other side with six statues of female figures (Caryatids), which were above the tomb of Cecrops, the legendary king of Athens.