The Kawah Ijen volcano in Java, Indonesia, is a spectacular (and dangerous) sight to behold. Unlike any other volcano in the world, Kawah Ijen emits what appear to be bright blue flames.
source/image: Great Big Story
This popular complex is situated within Ijen crater with stratovolcano Gunung Merapi as the highest point.
It is one of the world’s most unusual volcanoes because instead of producing the usual red lava and black smoke, its underground activities result in bright blue flames rising into the air.
Some people even call it electric blue fire.The glow is caused not by lava, but instead by sulfuric gases that create electric blue sparks when in contact with oxygen. Once the gases cool, bright yellow sulfur is formed, which is then mined and sold.
Although the surroundings look rather unfriendly – an acid lake and petrified sulfur in the caldera – they are useful. The Ijen caldera is used as the coffee plantations, since the soil is very fertile. And the sulfur mine extracts the minerals. The site is also frequently visited by the tourists.