Manjanggul Lava Tube

One of the world's longest lava tubes — 13km of underground passages

Manjanggul is one of the finest lava tube caves in the world — 13 kilometres long, with passages large enough to walk upright through for most of the accessible 1-kilometre section open to visitors. The tube formed when the outer crust of a lava flow hardened while molten rock continued to flow inside and eventually drained away, leaving a hollow tunnel.

Inside, the temperature stays at a constant 11°C year-round, which makes it a welcome escape in summer. The scale of the main passage is surprising — the ceiling in places exceeds 20 metres. Wear a jacket and non-slip shoes; the ground is wet and uneven. The site is on the northeast coast near Gimnyeong, about 30 kilometres from Jeju City. Open daily except Tuesdays; entry fee applies.

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A story
The lava column near the far end of the accessible section — about 7 metres tall — is described as one of the largest lava columns in the world. It formed when lava drained from the tube and the ceiling material gradually dripped and built up over thousands of years. It looks like something that should be behind glass in a museum but you just walk past it in the dark.