The Erechtheum is a famous ancient Greek temple located on the Acropolis of Athens. It has several synonyms that are commonly used to describe it, such as the Temple of Athena Polias, the Temple of Erechtheus, and the Temple of Poseidon-Erechtheus. The temple was constructed between 421 and 406 BCE and is known for its unique design, which includes both Classical and Ionic architectural styles. The Erechtheum is also famous for its beautiful sculptures and friezes, including the famous Caryatids, which were originally part of the temple's porch. Despite its age, the Erechtheum is still considered one of the most important and impressive ancient Greek temples in existence, and it remains a major tourist attraction in Athens today.