Kawah Ijen, Kalianyar, Sempol, Kabupaten Bondowoso, Jawa Timur, Indonesia
Kawah Ijen is a volcano that erupts what appears to be electric-blue lava flows. This surreal bright blue coloration is a result of a tweak of chemistry.Kawah Ijen Volcano, on the island of Java, Indonesia has two of the most unusual occurrences on Earth. The first is an active solfatara that emits hot, flammable sulfurous gases. These ignite as they enter Earth's oxygen-rich atmosphere and burn with an electric blue flame. Some of the gas condenses in the atmosphere to produce flows of molten sulfur that also burn with an electric blue flame. The flames are difficult to see during the day but illuminate the landscape at night.