Mount Paektu & Heaven Lake

PeaksRyanggang / Jilin border,North Korea

A volcano on the North Korea-China border holding a crater lake 384 metres deep, blown open in 946 and named in both Koreas' anthems.

September·Peaking now

Jul–Sep

The lake turns deep blue only now, between thaw and freeze. For three weeks around mid-July the alpine garden flowers at once, and all three slopes, the southern one included, are open. Come early: cloud hides the rim on most days.

Year-round The caldera, the waterfall and the steaming springs are here all year; the blue water and the bloom are not.

Mount Paektu is a volcano on the border between North Korea and China, and the lake in its crater sits at 2,189 metres and is 384 deep. The bowl holding it was blown open in 946, in one of the largest eruptions of the last five thousand years. That blast dropped five centimetres of ash on northern Japan, a thousand kilometres downwind. Because the year is known, geologists use that layer as a dated line through the ground: whatever lies under it is older, whatever lies above is younger. It turns up in Japanese lake beds and in Greenland ice. Sixteen shattered peaks ring the water, left standing when the rest of the summit went. There is no shelter on that rim, and the wind never lets up. The lake is sapphire only between thaw and freeze: ice holds it from mid-October to mid-June. Which mountain you climb depends on the side you come from. The routes in general use run up the Chinese flank, where the peak is called Changbaishan. The North Korean side is the sacred ground of the state. It is on the national emblem, leaders climb it before big announcements, and the country teaches that Kim Jong Il was born in a log cabin on these slopes under a double rainbow and a new star. Soviet records place that birth in the Far East. Both Korean anthems name the mountain. The climb crosses stacked climate belts in about an hour: broadleaf forest, spruce and fir, wind-twisted birch, and above about 2,000 metres a bare tundra where nothing grows taller than your boot. For three weeks around mid-July that grey ground flowers all at once between the lava blocks. The lake has one outlet. It squeezes through a notch in the caldera wall and falls in a roar you hear long before you see it. Downstream, groundwater heated inside the volcano comes up at 82°C, and stalls beside the path cook eggs in it. Two more rivers start here, the Yalu and the Tumen, and between them they draw almost the whole border this mountain stands on.

Worth knowing

Good to know

Give the lake more than one morning — cloud usually boils up over the rim after midday, and the odds swing wildly from day to day, so climb early and keep a spare morning in reserve.
The three Chinese slopes are not interchangeable — north for the waterfall and the hot springs, west for a long stairway to the widest rim view, south for the closest look at the water.
Dress for winter even in August — the rim hovers near freezing on a bright summer morning and the wind never really stops; in deep winter the summit drops below −30°C.
Avoid the July-August school holidays and the early-October national week — that is when the queues for the rim shuttles are longest, and a weekday outside those windows is a different mountain.

Things to do

1
Stand on the caldera rim above Heaven Lake
The last steps end at the crater edge, where the ground falls away to water lying at 2,189 metres in a bowl of bare rock. Sixteen shattered peaks close the ring, left standing when the rest of the summit went. There is no shelter up here and the wind never lets up.
2
Feel the thunder of Changbai Waterfall
Heaven Lake's only outlet squeezes through a notch in the caldera wall and comes down in a permanent roar you hear long before you see it. A trail runs up the valley towards the drop, past a bank of hard old snow that survives at its foot well into summer.
3
Climb from birch forest into Arctic tundra in an hour
The way up crosses the mountain's stacked climate belts: broadleaf forest, then spruce and fir, then wind-twisted Erman's birch, and above roughly 2,000 metres a bare volcanic tundra where nothing grows taller than your boot. Boardwalks carry you across the last of it, and for about three weeks around mid-July that grey ground flowers at once between the broken lava blocks, in what the Chinese side calls the alpine garden.
4
Boil an egg in the springs below the falls
Downstream of the waterfall, groundwater heated deep in the volcano surfaces at up to 82°C — hot enough that stalls beside the path cook eggs and corn directly in it. Meltwater runs in shallow channels past the steaming vents, and on a day when cloud hides the summit this valley is still worth the walk.