Kawah Ijen or Ijen Crater lake is the world’s largest highly acidic lake located at Banyuwangi, East Java. Kawah Ijen has a lake 36 million cubic meters of sulfuric acid and hydrogen chloride. Ijen caldera floor covered by Coffee plantations and drawn tourists to its waterfalls, hot springs, and dramatic volcanic scenery. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an E-W-trending zone across the southern side of the caldera.

Kawah ijen sulfur.

On the edges of the lake, the fumaroles (volcanic gas eruptions) depose 4 tonnes of sulfur daily. Kusatsu-Shirane (Japan) and Poas (Costa Rica) are another acid lakes, but the Ijen Crater lake is the largest acid lake on Earth, having a maximum depth of 212m (706ft). These lakes result from the mix of rainfall water with gases coming from the depths of the volcano.

Sulfur miner at Kawah Ijen.

The walls of the Kawah Ijen lake are light ocher, but the water has a turquoise color, with emerald reflexes. The temperature of the water is of 340 C, and sulfur bubbles float on the surface. Sulfur powder covered  surroundings area. The smell is pungent and irritating, filled with sulfur dioxide.


Bluefire of Ijen crater

The phenomenon of blue fire in ijen occurs when oxygen meets natural gas at a certain temperature. The Blue Fire phenomenon in the Ijen Crater may have existed for hundreds or even thousands of years ago. However, its existence was only known to the public around the 1950s. Most likely the inventors were local residents who were mining sulfur because the Ijen Crater was a traditional sulfur mine area.

People from the neighboring area extract sulfur from the crater manually. Each worker can transport 40 to 70kg (90 to 155 pounds) at once on the abrupt slopes of the volcano, using bamboo ladders where the slope is too steep. In one day, a man can carry up to 360 kg (750 pounds) of sulfur. The daily production of the exploitation is just of 4 tonnes, a derisory quantity, if we consider the fact that the crater harbors 30,000 tonnes of sulfur. Industrial exploitation of the lake has not been planned so far, as the volcano erupts from time to time, projecting acid to the height of 600 m (2,000 ft) and splashing the neighboring areas with a corrosive rain.

Kawah Ijen Blue Fire.
Kawah Ijen Blue Fire.

Blue Fire Tour

Kawah Ijen Tour or Ijen Crater Blue fire tour can start from Ketapang harbor, Train Station, Bus Terminals, Hotel or After visit mount Bromo.
walk about 2 hours from the entrance to the ijen crater, to enjoy the blue fire before sunrise. Blue fire only occurs when the night before sunrise so the tour starts at midnight. For Ijen crater tour package you can choose from option below :

  • Ijen Blue fire midnight tour.
  • Ijen crater overnight tour.
  • Bromo Ijen tour.
  • Bromo Ijen Malang tour.

Tour Request


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