Sounion is a rocky cape, the southernmost point of Attica. It is the first piece of land one can see sailing from the Cyclades and Asia Minor to Piraeus. The site of Sounion was inhabited since the prehistoric times. From the 8th century BCE however, the cult of Poseidon and Athena started being cultivated. The existence of a sanctuary is perhaps even earlier. Homer refers to “Sounion sanctuary” (Odyssey, c 278) where was the tomb of the hero Frontis (captain of the ship of Menelaus, who died on the return journey). In the 6th century BCE the first temples were constructed. In 480 BCE the Persians invaded Attica destroying the sanctuaries at Sounion. After the Battle of Salamis (28 or 29 September 480 BCE) the Athenians positioned an occupied Phoenician warship at the top of the hill as a trophy but also as an indication of their maritime power. ( source )