The Acropolis is a flat-topped rock which raises 150metres above sea level in the city of Athens. Artifacts date back to the End of the Stone Age and it combines several buildings like the Parthenon, the Erechtheion and the Temple of Athena Nike. During the 11th century BCE the citadel became a centre of worship and in the 5th century BCE the acropolis gained its final shape. The main architect was Mnesicles, a colleague of Phidias and it was used as a monument to the cultural and political achievements. The Acropolis is open for the public from 8am to 6:30 pm every day.