Ijen Volcano or known as ‘Ijen Crater’ or ‘Kawah Ijen’ has elevation 2,769m (9,085 ft) which located in East Java, Indonesia. Highly recommended for mountain buffs and hikers. Ijen is a quiet but active volcano, and the landscape is dominated by the volcanic cones.
Waking up in the middle of the night and trekking up, you will find interest things. Around 2 a.m. when the first miners begin their ascent, hundreds of tourists are already streaming across the flanks of Ijen to witness its iconic blue flames, which can only be seen at night. Its half-mile turquoise crater lake takes on an eerie glow in the darkness.
The initial hike up from the start point to the rim of the crater takes 60 to 90 minutes at moderate pace to cover the 3km distance. The path itself is in good condition and in most places is quite wide and smooth. Add a gas mask and walk into a gas cloud of sulfur while watching blue flames by the lake.
To get the lake, it takes an extra half an hour to descend into the crater via a much more technical and mostly single track to the lake’s edge where you can see the sulfur mining operation. In recent decades, the miners themselves have become a tourist attraction.
At night, when you reach the edge of the lake, you will see a blazing blue light. Dazzling, electric blue flame can often be seen streaming down the mountain. The glow is actually the light from the combustion of sulfuric gases. Those gases emerge from cracks in the volcano at high pressure and temperature—up to 1,112°F (600°C).
When they come in contact with the air, they ignite, sending flames up to 16 feet (5 meters) high. Some of the gases condense into liquid sulfur which continues to burn as it flows down the slopes.
If you get up close, be wary of the noxious fumes – some sort of face mask is recommended and even if the fumes are blowing in the opposite direction, a quick wind shift can mean you are very quickly engulfed by burning fumes
After the gases condense into liquid sulfur which then flows and solidifies into hard sulfur mats, the miners break it up and haul it off the mountain on their backs. There are loads of sulfur seen on the crater rim and when you come back down, you will see many miners carry the sulfur to the sulfur shelter.
The miners sell the sulfur for about 600 Indonesian rupiah per kilo (less than 25 U.S. cents per pound). They can carry loads of 176 to 220 pounds (80 to 100 kilos) once a day or twice if they work into the night. You can also buy small pieces of sulfur carved into various ornamental shapes which make a nice souvenir.
Mount Ijen hosts one of the last remaining active sulfur mines in the world, and while its otherworldly vistas have captivated scientists and travelers for more than two centuries.
Lake of Ijen Crater
The lake inside the crater is the world’s largest highly acidic crater lake. Kawah Ijen Crater Lake contained hydrochloric acid. In fact, it’s the acid that makes the water green. the pH of the water is less than 0.3, which means it is capable of dissolving metal – so you definitely don’t want to be going for a swim here!
You like a guarantee that you will go down the crater on the day of your trip. There is no guarantee, nature is unpredictable and if due to massive sulfur clouds it is too dangerous on that day to go down, you have to respect it for your own safety.
Sunrise is beautiful up here, the colors of the lake are highlighted. Once you witness its blue flames which disappear at 5 am, you can watch the sunrise and take in some amazing views, including another view of the lake and surrounding area outside the crater which is relatively lush and forested compared to the more barren areas of the crater itself.
Don’t forget to wear warm clothes, the weather is very cold up there. Although you will sweat in the hiking, it is best to keep wear warm clothing.
Remember to bring a mask to cover your nose when you see the Blue Flames as the pungent odor of sulfur may burn.
Is it a difficult hike? Actually no, you don’t need to have climbing experience or an extraordinary level of fitness to be able to climb Ijen, but if you already get out of breath, rest for a while and continue the journey when you begin to stabilize.
Ijen Crater was amazing if you are fit and can cope with the sulfur that a bit of a rough, but manageable trail down, then go for it, as it is so amazing and almost unique in the world.
There is a Banyupahit river located west of Ijen Crater, you might be interested to visit it. It is a river with water that leaves the crater lake through rare overflows or through groundwater seepage enters the drainage basin of the river.
Banyupahit River (Acidic Streams Below the Caldera)
Water enters the caldera lake as rain and as runoff from a limited drainage area. Water and gases also enter through hydrothermal vents on the bottom of the lake. Rarely, overflow water goes over a spillway on the west side of the lake and into the Banyupahit River drainage basin.
Water also leaves the lake through underground seepage and enters tributaries of the Banyupahit River. As this water enters the drainage basin, it has a pH and dissolved metals content similar to the caldera lake.
Banyupahit river has a significant detrimental effect on the downstream river ecosystem. But many local tourists who make this location as a tourist destination.
Ijen Crater is an amazing natural beauty. If you are a hiker or mountain buffs, maybe you should try to conquer this mountain. Is it a difficult hike? No, you don’t need to have climbing experience or an extraordinary level of fitness to be able to climb. Be sure to wear warm clothes and bring a gas mask to protect your body from sulfur gas when you witness the phenomenon of blue flames. Enjoy the beautiful views of Sunrise, the lake and the surrounding area outside the crater.