What civilizations was at its height around 500BC?

Around 500 BC, several civilizations were at their height, including the Persian Empire, which was expanding under Cyrus the Great, and the Greek city-states, notably Athens, which was flourishing culturally and politically. In India, the Mahajanapadas, or great kingdoms, were emerging, while the Chinese Zhou Dynasty was in its later stages, characterized by the philosophical developments of Confucianism and Daoism. Additionally, the Mesoamerican Olmec civilization was significant during this period, known for its monumental stone heads and influence on later cultures.