Flaming sulfur from Kawah Ijen volcano, Indonesia (© Martin Rietze/Alamy)

【March 19 2015】To the vexation of volcanologists, geologists, and science enthusiasts the world over, many discussions of Kawah Ijen volcano incorrectly refer to its glowing flows as “blue lava.” Kawah Ijen, on East Java, Indonesia, spews super-heated sulfur, which emerges from fissures in the volcano’s crater as sulfuric gas, not lava. When the gas reacts with oxygen in the air, it combusts, creating these dazzling neon-blue flames. The blue flames are blazing nearly all the time, but visible only at night.Explore breathtaking Gallery from the HuluTrip homepage over the past 5 years..