Stunning summits await at Hallasan Mountain, which sits at the centre of Jeju Island. Also called Yeongjusan (meaning ‘mountain high enough to pull the galaxy’), this national geopark proudly takes the title of South Korea’s tallest mountain at almost 6,400 feet (1,950m) above sea level. It's home to 1,800 types of plant and 4,000 species of animal, and is topped with a famous crater lake. Immerse yourself in the mountain’s enchanting environment on the Seongpanak (6 miles/9.6km) or Gwaneumsa (5.4 miles/8.7km) trails. The trails are well-maintained, but, as with all mountains, research your route thoroughly before attempting.