Kawah Ijen’s Blue Fire is a natural sulfur fire inside a volcanic crater in East Java, Indonesia. Hot sulfur gases escape through cracks and ignite on contact with the air, producing electric-blue flames visible at night. Some gas condenses into liquid sulfur and continues burning as it flows downhill, creating the illusion of blue lava. By daylight, the blue disappears and the cooled sulfur is bright yellow.
Kawah Ijen’s Blue Fire
