Sunset is the best time to arrive at the 5th-century-B.C. Temple of the mythical sea God Poseidon. Perched on cliffs above Cape Sounio, the temple ruins, surrounded on three sides by sea, have stunning views out over the Aegean. It was mentioned in Homer's epic poem, The Odyssey. More recently, English Romantic poet Lord Byron visited this atmospheric spot in 1811 and inscribed his name at the base of one of the temple's Doric columns.