Indonesia
Ijen Crater
Sulphur miners and blue fire share Ijen's crater with a kilometre-wide acid lake.
Torches bob up the trail in the dark, and at the rim the day arrives over a pale crater wall and a kilometre-wide acid lake the colour of oxidised copper. The air tastes faintly of sulphur while the light builds.
Kawah Ijen holds a kilometre-wide acid crater lake at 2,386 metres in East Java, its colour the product of an extreme chemical environment. The visit is regulated: published gate hours from 02:00, online booking and a health requirement, with the authorised route running to the rim and closures possible at any time for gas or volcanic activity. Sulphur miners still work the mountain, and the blue fire that made Ijen famous burns in gas vents below the rim, a sight that belongs to darkness. Banyuwangi is the gateway town, with the Bali ferry beyond it.
Solo
A licensed pre-dawn departure handles the timing, and the rim walk sets its own pace.
Friends
Company makes the 2am start easier, and the rim is wide enough to spread out along.
- The crater lake is around a kilometre wide, among the largest highly acidic lakes on Earth.
- Dawn at the rim delivers the lake's colour before cloud and heat arrive.
- The walk up from Paltuding is about ninety minutes of steady volcanic trail.
- Banyuwangi below is the gateway to the Ijen Geopark and the Bali ferry.
Nasi tempong, rice with fried sides and a furious sambal, is Banyuwangi's plate for after the hike.
The legal visit starts at 02:00, hours before kitchens open, so water and an early bite ride up with you.
Pico de Orizaba
Mexico
Mexico's highest mountain rises from forest routes to a serious high-altitude summit.
Sarek National Park
Sweden
Europe's wildest corner — no trails, no huts, no bridges; glaciers and river fords alone.
Vinicunca
Peru
Sediment bands of red, ochre and pale green striping bare rock above 5,000 metres.
Skippers Canyon
New Zealand
A gold miners' road carved into sheer cliff, best driven by someone else.
Seram Island
Indonesia
Maluku's mother island rises roadless from the coast, walked only with its hosts.
Jomblang Cave
Indonesia
A sixty-metre rope descent reaches a sinkhole forest lit by one shaft of sun.
Mentawai Islands
Indonesia
Sago smoke in the longhouse, heavy water on the reef: the Mentawais run two worlds.
Morotai
Indonesia
Wartime aircraft rest on Morotai's reefs, coral colonising the cockpits.