Acropolis. Athens. Greece. View of the elegant North porch Ionic columned portico of the Erechtheion on the Acropolis summit. Built between 420 and 406 BC, the elegant and unusually shaped Temple was designed to incorporate a number of ancient sanctuaries and cults including that of Athena and her olive tree and Poseidon-Erechtheus. The Erechtheion Temple was part of the monumental rebuilding and transformation of the Acropolis buildings during the time of Perikles. The Acropolis of Athens and its monuments are a UNESCO World Heritage Site.