Santorini is one of the Mediterranean's most dramatic islands: a flooded caldera (a collapsed volcanic crater) with a long, steep, multicolored arc of cliffs, thrusting up a thousand feet above sea level. Sometimes called "The Devil's Isle," this unique place has captured visitors' imaginations for millennia and might have inspired the tales of Atlantis. But the otherworldly appeal of Santorini doesn't end with its setting. Perched along the ridgeline is a gaggle of perfectly placed whitewashed villages, punctuated with azure domes, that make this, undeniably, one of Greece's most scenic spots. If this place didn't exist, some brilliant fantasy painter would have to conjure it up.