Kawah Ijen (Ijen Crater)
A pre-dawn climb to the world's largest acidic crater lake and its rare electric-blue sulfur flames
- Difficulty
- Moderate
- Duration
- About 6-7 hours round trip, starting around 1am for the pre-dawn blue fire
- Summit elevation
- 2799 m
Ijen's crater holds a turquoise lake of near-pure sulfuric acid, ringed by cliffs where miners still haul sulfur blocks out by hand. Climbers set off in darkness to reach the rim before dawn, when escaping sulfuric gas ignites into the ghostly blue flames the volcano is famous for, fading as daylight returns.
Highlights
- The blue fire phenomenon, visible only in pre-dawn darkness
- One of the world's largest highly acidic crater lakes
- Traditional sulfur miners working the crater floor
- Sunrise views back across the Ijen plateau
Getting there
Fly into Banyuwangi (closest) or Surabaya, then transfer by road to the Paltuding trailhead near Licin, roughly 1.5 hours from Banyuwangi town.
Safety tips
Sulfuric gas can gust suddenly and is genuinely harmful; carry or rent a proper gas mask, keep well back from the crater floor edge, and turn back if fumes thicken. The medical certificate requirement exists because the altitude and gas exposure are unsuitable for some visitors.
What to bring
- A proper gas mask, not just a cloth covering
- Headlamp for the pre-dawn ascent
- Warm layers for the crater rim before sunrise
- Passport and medical certificate for the checkpoint