The Erechtheion derived its name from a shrine dedicated to the legendary Greek hero Erichthonius. It is an intricate temple. It sprang from a complex plan that was designed to accommodate the radically uneven ground on the site, and to avoid disturbing sacred shrines like the altars to Poseidon (Erechtheus), and Hephaestus, or the spot where Poseidon hit the Acropolis with his trident. Other shrines that needed to be accommodated included the sacred olive tree, a well containing sea water (the Erechtheian Sea), the tomb of Cecrops, and the Pandrosion sanctuary. Its completion found Athens at the mercy of Sparta, and its treasury depleted. By no means however did the splendor of the Athenian cultural achievements cease to shine as evident in their influence on the art and architecture of the next two and a half millennia.

The word irregular, which has been used to describe the Erechtheion, bears a different meaning to the term in its current usage. It meant that the building was built to accommodate a plan highly unusual for a temple or for any building of worship. Positioned on a sloping site north to the Parthenon, and housing three deities, an unusual plan was required.

The building of the Erechtheion concluded the ambitious building program initiated by Pericles, during a time that the Athenian empire enjoyed unprecedented political and cultural influence. It is built of Pentelic marble and was designed by Mnesicles. The decoration throughout is varied and shows exquisite detail and craftsmanship. The building was greatly damaged when it was transformed into a byzantine Christian church in the 7th century AD. Later, during Latin rule, it was converted for use as a palace; during Ottoman rule it was a harem, and in January of 1827 a Turkish cannon ball further damaged the building.