
The Temple of Poseidon at Sounion was a temple dedicated to the god Poseidon within the Sanctuary of Sounion in Attica, Greece. It was one of the major monuments of the Golden Age of Athens, and it was often visited by sailors praying for safe passage on the seas. In 431 BC, the mercenary Kassandra assassinated the Cult of Kosmos leader Okytos the Great outside of the temple.