Known as the blue flame/blue fire, it is a blue colored flame that is produced from the sulfur that is released when it burns. It burned as an electric-blue flame that had the illusory appearance of lava. If one want to see these blue flames, one actually must see them at night time – they aren’t significantly seen within the daylight.
Locals carry out sulfur mining here by hand carrying baskets filled with sulfur from the crater soil. Ijen Crater has the largest blue fire chamber in the world
At its peak, you'll see the sun rise over the crater with the world's largest acid lake, Kawah Ijen, in a brilliant turquoise color.
There is no place in the world like that!