Bundok Ijen

The Ijen hike is generally considered moderate, but can be challenging due to its length, steepness, and rocky, uneven terrain, especially at night. Hikers face about 3.5 km (2.2 miles) and 600 meters (1,981 ft) of elevation gain to the crater rim, with a further steep and slippery descent into the crater to see the blue fire. A decent level of fitness and sturdy hiking shoes are essential, and some hikers may find the night conditions and sulphur fumes particularly strenuous. The trail to the crater rim is about 3.5 km with ~600m (1,981 ft) of elevation gain, with a further steep descent to the blue fire. The path is rocky, uneven, and often slippery, especially the path into the crater. Hiking in the dark requires navigating the trail carefully and is a significant challenge.

The "blue flame" phenomenon in the Ijen Crater is a mesmerizing and rare natural occurrence. It is caused by the combustion of sulfuric gases released from the volcano's vents, which ignite and burn with a striking blue hue. This natural spectacle is a significant draw for visitors to the Ijen volcano.

Visiting Ijen Crater involves health and safety risks. The gases emanating from the crater can be nauseating and are toxic, so it is important not to breathe in too much of the sulfurous fumes. Visitors should take precautions, such as wearing protective masks, especially when descending into the crater. Following safety guidelines and listening to local guides is crucial for a safe experience.

Mount Ijen Crater will be closed to visitors on the first Friday of each month throughout 2025. These closure dates include: January 3, February 7, March 7, April 4, May 2, June 6, July 4, August 1, September 5, October 3, November 7, and December 5.

For your trip to Gunung Ijen in 2025, pack layers of warm clothing as temperatures can be cold, especially at night. Sturdy hiking shoes with good grip are essential for the uneven terrain. Bring a headlamp or flashlight for the dark hike, a mask to protect against sulfur fumes, and a water bottle. A camera to capture the stunning views and blue fire is also recommended.