JEJU ISLAND

Jeju province encompasses the South Korean island of Jeju in the Korea Strait. It's known for its beach resorts and volcanic landscape of craters and cavelike lava tubes. Hallasan Mountain, a dormant volcano, features hiking trails, a crater lake at the 1,950m summit and nearby Gwaneumsa Temple. The Geomunoreum Lava Tube System includes 7km-long Manjanggul Cave, created centuries ago when Hallasan was still active.