Indonesia · East Java
Kawah Ijen
A turquoise acid lake and blue fire.
Kawah Ijen features in this Unreal Places episode · real footage, no AI imagery
Why it looks like this
- The turquoise crater lake is one of the most acidic lakes in the world.
- At night the crater glows with "blue fire": burning sulphur gas, one of very few places on Earth you can see it.
How to actually go
- Blue-fire hikes start in the middle of the night; go with a guide and a proper gas mask.
- Closures happen when gas levels are high; check conditions before you travel.
Best time: April to October (dry season).
