This UNESCO World Heritage site is a must-visit if you are exploring Jeju or if you are a nature enthusiast or perhaps a geology aficionado. Manjanggul Cave is one of the most thrilling and largest lava tubes in the world. Although it stretches for 7.4km, only the first kilometre is open to the public. If this activity doesn’t sound like you, we suggest you put your adventurer hat (and your trekking boots) on.

