Volcanic Jeju, one of the Korea’s most popular destinations, may come as a surprise to many travelers visiting the country. This island with a mild climate and stunning beaches sits off the southwestern corner of the peninsula, an hour’s flight from Seoul. Bring your hiking boots or, at least, walking shoes. One of the highlights of the island is Jeju Olle, a network of more than 250 miles of well-maintained trails. Most follow the island’s coastline and include some of the best vistas while passing through all of Jeju’s various landscapes, from farms to forests.