Kawah Ijen is an active volcano on the island of Java with an extremely acidic crater lake and gas emissions that produce blue flames upon contact with oxygen in Earth's atmosphere.

Only the U.S. (168) and Russia (144) have more. Essential packing list: We landed in Java and drove for three days to reach Mount Ijen. While preparing for the trip, I learned that the sulfurous ...

Ijen has become a well-known tour destination ... In 2019, a China university student died from falling down Huashan Mountain ...