Another item on Pericles' agenda for the Acropolis was the rebuilding of a small shrine (destroyed by the Persians) that had housed the venerable cult statue of Athena Polias. But what with the outbreak of the Peloponnesian War, and Pericles' own death, this rebuild was long delayed.
Work on the Erechtheum started in 421. It was completed, not without interruptions, in
Many cults found a home in the Erechtheum, and they were ones deeply rooted in Athenian tradition. This is reflected in the building's composite architecture. On the east front, for instance, there was a stoa of six columns that gave access to the cella protecting the statue of Athena Polias. To the north, there was a stoa of four by two columns that gave the visitor access to the entrance-hall and the cella sacred to Poseidon and to Erechtheus himself. On the south front there was (and still is) a porch in the form of a grave monument, standing over Cecrops' Tomb. The originality of this was that to carry the roof it made use not of columns, but of six figures of young girls - the celebrated Caryatids. On the west front there were three great windows framed by Ionic semicolumns. Just below the windows were: the sanctuary of Pandrosus; the Sacred Olive - Athena's present to Athens; and very likely the 'Sea of Erechtheus' - the spring of brackish water that gushed up when Poseidon struck the ground with his trident. The Erechtheum also housed the altars of Zeus 'Hypatos', Hephaestus, the hero Boutes, and Zeus 'Hercius'. One or other of these locations also housed a wooden image of Hermes and a famous golden lamp made by the sculptor and gold- and silversmith Callimachus.
The top of the walls and columns was embellished not only with a frieze but with elaborate plant patterns; and so were the windows (perithyron). The architectural detail was frequently picked out in colour: red, blue, gold. The north and south entrances still have their original marble coffered ceilings.