By day, Kawah Ijen looks much like any other active volcano. But after sunset, its crater is transformed by electric-blue flames that flicker across the rocks, drawing travellers from around the world to witness one of Earth's rarest geological spectacles. The striking display has made Kawah Ijen one of Indonesia's best-known natural attractions, yet what many mistake for glowing blue lava is actually something entirely different. According to volcanologists and the US Geological Survey (USGS), the colour comes from sulphur-rich volcanic gases that ignite as they escape through cracks in the ground, burning at temperatures that can exceed 600°C.
Get breaking news anytime, anywhere. Download the TOI app now!
