The Ijen volcano complex is a group of stratovolcanoes in the Banyuwangi Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide. The Gunung Merapi stratovolcano is the highest point of that complex.

The name "Gunung Merapi" means "mountain of fire" in the Indonesian language (api being "fire"); Mount Merapi in central Java and Marapi in Sumatra have the same etymology. West of Gunung Merapi is the Ijen volcano, which has a one-kilometer-wide turquoise-colored acidic crater lake.

The lake is the site of a labor-intensive sulfur mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is paid well considering the cost of living in the area, but is very onerous. Workers earn around Rp 50,000 - 75,000 ($5.50-$8.30) per day and once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Paltuding Valley to get paid. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones run east-west across the southern side of the caldera.

The active crater at Kawah Ijen has a diameter of 722 metres (2,369 ft) and a surface area of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft). The lake is recognised as the largest highly acidic crater lake in the world. It is also a source for the river Banyupahit, resulting in highly acidic and metal-enriched river water which has a significant detrimental effect on the downstream river ecosystem. In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid

Blue Fire Crater Since National Geographic mentioned the electric-blue flame of Ijen, tourist numbers increased.[citation needed] The phenomenon has occurred for a long time, but beforehand there was no midnight hiking. A two-hour hike is required to reach the rim of the crater, followed by a 45-minute hike down to the bank of the crater. The blue fire is ignited sulphuric gas, which emerges from cracks at temperatures up to 600 degrees Celsius (1,112 degrees Fahrenheit). The flames can be up to 5 meters (16 feet) high; some of the gas condenses to liquid and is still ignited. It is the largest blue flame area in the world and local people refer to it as 'Blue Fire'

Sulfur mining at Ijen
An active vent at the edge of the lake is a source of elemental sulfur, and supports a mining operation. Escaping volcanic gases are channelled through a network of ceramic pipes, resulting in condensation of molten sulfur. The sulfur, which is deep red in color when molten, pours slowly from the ends of these pipes and pools on the ground, turning bright yellow as it cools. The miners break the cooled material into large pieces and carry it away in baskets. Miners carry loads ranging from 75 kilograms (165 lb) to 90 kilograms (200 lb), up 300 metres (980 ft) to the crater rim, with a gradient of 45 to 60 degrees and then 3 kilometers (1.86 miles) down the mountain for weighing. Most miners make this journey twice a day. A nearby sugar refinery pays the miners by the weight of sulfur transported; as of September 2010, the typical daily earnings were equivalent to approximately $13 US. The miners often receive insufficient protection while working around the volcano and complain of numerous respiratory afflictions. There are 200 miners, who extract 14 tons per day - about 20 percent of the continuous daily deposit.

What the adventure look like?
One of the visitors attention in the area of ​​the crater, the existence of Blue fire traditional sulfur miners. The workers dared to approach the lake to dig sulfur with simple equipment and then carried with a basket. The sulfur miners take sulfur from the bottom of the crater. Here the smoke is quite thick, but the degree necessary equipment such as gloves masks, they are still looking for molten sulfur. The molten sulfur obtained from the pipe leading to the source of volcanic gases that contain sulfur. This gas is then piped out in the form of molten sulfur red and yellow sulfur after freezing. Once the sulfur is cut, the miners would carry through the path. Heavy burden borne between 80 to 100 kg. The miners are accustomed to bear this heavy burden while down the path on the cliffs of the caldera down the mountain as far as 3 kilometers.

This activity requires extra effort, please prepare yourself before starting this activity. Ijen crater blue fire tour is divided into two different types of tour packages. Please choose according to desire and the time you have.

1 day 1 night Ijen crater blue fire tour Pick up will start between 08.30pm – 11.00pm. Depart to Gilimanuk port which takes approximately 3 hours drivIMG_6770e. Crossing will done using passenger ship (ferry) to the island of East Java (Ketapang).
It took approximately 45 minutes to 1 hour to arrive at the port of Ketapang, Banyuwangi. 2 hours of driving longer needed to reach the start point of trekking. Before the journey begins, guides who stood guard post will give you a small illustration of the situation in this area.
It only takes about 1,5-2 hours to reach the Ijen crater. We can also take a closer look to the Ijen crater dropped following sulfur carrier workers. After enjoying the blue fire and charm of Ijen crater, we could go back to the start point to go back to Bali. We will arrive in Bali in the afternoon or evening (Depending on the traffic condition).

- 2 person sharing Price: Rp. 4.300.000/2.150.000/pax
- 3 person sharing Price: Rp. 4.950.000/1.650.000/pax
- 4 person sharing Price: Rp. 5.850.000/1.462.500/pax

Price is included:
- Pick up service from Bali & transfer out back to Bali
- Entrance fee
- Land transportation with driver and fuel during the trip
- 4WD vehicle (jeep) for Ijen Crater Tours
- Mineral water, entrance tickets, guide
- Cost for ferry from Bali to Java Island / return - gas mask

Price is not included:
- ravel Insurance, Camera fee at Ijen Crater
- Bar, Laundry, Phone call, Internet, Tipping & other personal cost
- Cost for lunch & dinner during the trip
- tipping guide & Driver