Ancient name for a shrine identified by most (but not all) scholars with the third outstanding building on the Athenian Acropolis, begun in 421 bce and finished, after a lapse, in 407 bce; built of Pentelic marble (see pentelicon), with friezes of black Eleusis stone to take applied white marble relief sculpture. Exact details of its construction are known from a contemporary inscription (IG 13. 474). The main structure is divided into four compartments: the largest (east cella) has a prostyle-hexastyle Ionic portico; the west end is closed by a wall with engaged columns and corner piers. At this end is a unique and boldly projecting (though small) south feature—the ‘porch of the maidens (korai)’, with draped female figures serving as supports—and, nearly opposite on the north side, a still more boldly projecting porch with Ionic columns (partly reassembled in early 20th cent.) standing on a lower level and having the tallest order of the whole composition.
The Erechtheum replaced to some extent the large 6th-cent. temple of Athena whose foundations can be seen between it and the Parthenon: hence the appellation ‘the ancient temple of Athena Polias’ in some Greek sources, including Athenian inventories of its treasures. It housed (see Paus. 1.26.5–27.3) a number of ancient cults (this may partly account for its complicated form) and many sacred spots and objects—the venerable image of Athena Polias, a golden lamp made by Callimachus (2), a salt well and the mark of Poseidon's trident, an altar of Poseidon and Erechtheus, and altars of Butes (1) and Hephaestus. Near the west end of the building were shrines of Cecrops and Pandrosus, and the original sacred olive of Athena.
The Erechtheum was much admired in antiquity: the korai called Caryatids by the Romans were copied for the forum Augustum and Hadrian's villa at Tibur; the Athenians faithfully replicated its details in their temple to Roma and Augustus.