1. Kawah Ijen, the volcano with blue lava
Saving best for the last, we present you with Kawah Ijen, a volcano that spits out distinctly blue lava. There is a sulfur mine built in volcano. The blue lava isn’t actually lava; it is sulfur.
The sulfuric gases inside the volcano heat up and they shoot through. At first blue flames rise about 5 meters in the air. The gases then cool down and form a liquid sulfur. The liquid sulfur is a majestic looking blue liquid flowing like a lava from the volcano.
The air is toxic and you need gas masks to work in the mine or wander around it. This hasn’t happened anywhere else in the world. It is a truly unique and marvelous spectacle.