Mount Ijen is very well-known by tourists as Kawah Ijen with the 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 between 300-500 feet tall and it has 4 times erupted in 1796, 1817, 1913, and 1936. Ijen crater is comprised of Ijen volcanic craters and highlands. This Kawah Ijen lies in the East Java area and the location exactly is in 3 districts area, they are Bondowoso, Situbondo, and Banyuwangi district.
Ijen volcano has sulfur mining indicates an active volcano with magma under the ground. When a visitor reaches on 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 of the largest volcano sulfur in the world. That could produce 36 million cubics of sulfur and hydrogen chloride with an area of approximately 5.466 hectares. Mount Ijen has outstanding natural beauty with turquoise color sulfur lakes with a dramatic and elegant touch. The Ijen lake has zero acidity with a depth of 200 meters, strong acidity could dissolve clothing and human fingers as well.