Kawah Ijen is very well-known by tourists as Kawah Ijen with a blue flame, and it is one of the most active volcanoes in Indonesia. The Ijen crater has a height of 2.443 meters above sea level. The walled caldera is between 300-500 feet tall and has been four times erupted in 1796, 1817, 1913, and 1936. Ijen crater comprises Ijen volcanic craters and highlands.
This Kawah Ijen lies in the East Java area, and the location is in 3 districts: Bondowoso, Situbondo, and Banyuwangi district. Ijen volcano has sulfur mining, which indicates an active volcano with magma under the ground. When visitors reach the top of Mount Ijen, they can see the sulfur miners working, busy carrying piles of sulfur on their backs with a steep path. The Lake of Ijen is the center's biggest volcano sulfur in the world. That could produce 36 million sulfur and hydrogen chloride cubics with an area of approximately 5.466 hectares.
Mount Ijen has outstanding natural beauty with turquoise-colored sulfur lakes with a dramatic and elegant touch. The Ijen Lake has zero acidity at 200 meters depth with strong acidity and can dissolve clothing and human fingers.