Poseidon (Greek: Ποσειδῶν) was the god of the sea, and, as "Earth-Shaker," of the earthquakes in Greek mythology. The name of the sea-god Nethuns in Etruscan was adopted in Latin for Neptune in Roman mythology: both were sea gods analogous to Poseidon. Linear B tablets show that Poseidon was venerated at Pylos and Thebes in pre-Olympian Bronze Age Greece, but he was integrated into the Olympian gods as the brother of Zeus and Hades. Poseidon has many children. There is a Homeric hymn to Poseidon, who was the protector of many Hellenic cities, although he lost the contest for Athens to Athena.
Cape Sounion (Modern Greek: Aκρωτήριο Σούνιο, transliterated Akrotírio Soúnio, pronounced [akroˈtirʝo ˈsuɲo]; Ancient Greek: Άκρον Σούνιον, Άkron Soúnion; Latin: Sunium promonturium; Venetian: Capo Colonne - "Cape of Columns") is a promontory located 69 kilometres (43 mi) SSE of Athens, at the southernmost tip of the Attica peninsula in Greece.
Cape Sounion is noted as the site of ruins of an ancient Greek temple of Poseidon, the god of the sea in classical mythology. The remains are perched on the headland, surrounded on three sides by the sea. The ruins bear the deeply engraved name of English Romantic poet Lord Byron (1788–1824).
The site is a popular day-excursion for tourists from Athens, with sunset over the Aegean Sea, as viewed from the ruins, a sought-after spectacle.