Seeking the secret of eternal youth? You might find it on Ikaria, one of the most remote, undeveloped and unusual islands in the Aegean Sea. Named after the myth of Icarus, the boy who flew too close to the sun, Ikaria is one of the world's so-called 'blue zones'; alongside Sardinia (Italy), Okinawa (Japan), Nicoya (Costa Rica) and Loma Linda (USA), the island's fiercely self-sufficient residents are notoriously long-lived, and a high percentage survive well into their nineties. While still slightly neglected by the Greek ferry network, this isolated isle, with its secret beaches, thermal springs and plant-rich diet, is worth the odyssey.