This is the The Erechtheion on the the Acropolis hill, so called the "Sacred Rock" of Athens.was built in ca. 420 B.C. in the Ionic order. It has a prostasis on the east side, a monumental propylon on the north, and the famous porch of the Caryatids on the south. The main temple was divided into two sections, dedicated to the worship of the two principal gods of Attica, Athena and Poseidon-Erechtheus.