In ancient times the acropolis was the public centre of Hellenic cities. It was usually built on a higher and fortified site. The most remarkable is the Acropolis of Athens, illustrating the civilizations, myths and religions that flourished in Greece over a period of more than 1,000 years. It is the site of four of the greatest masterpieces of classical Greek art – the Parthenon (a temple of Athena Parthenos), the Propylaea (a marble staircase with colonnades), the Erechtheum (the tomb of Erechtheus and a temple of Poseidon) and the Temple of Athena Nike