Very little remains of the Temple of Poseidon, located in the north of Poros. What was once a big Doric temple is largely in ruins today. An earthquake in 395 AD destroyed much of the temple. The temple dates to the 6th Century BC and functioned as a government center for some of the formation of a league for North Peloponnese states. Famous orator, Demosthenes, committed suicide here to escape in 322 BC, to escape capture by the King of Macedonia.