The striking coastline of Omijima Island has earned it the nickname the Alps of the Sea. Its sheer cliffs and dramatic angles certainly echo the skyscraping peaks in that European mountain range. But a visit to Omijima Island will take you to the other side of the world, to Kita-Nagato Kaigan Quasi-National Park, in Yamaguchi Prefecture, Japan. Year-round scuba diving adventures reveal a world under the waves just as beautiful as the one above the surface.