In the dark before dawn, burning gas glows blue on the floor of a crater in eastern Java, beside the largest body of hyperacidic water on Earth. Kawah Ijen reopened on 28 September 2026 after a month of fire closures, with stricter booking and health rules than many older guides describe. This is what the night actually involves and how to plan it properly.
Is Kawah Ijen open right now?
Yes. Taman Wisata Alam Kawah Ijen, the nature recreation park around the crater, reopened on 28 September 2026 after closing on 4 September because of forest and land fires on the mountain. The park authority, BBKSDA Jawa Timur, reopened it once the emergency response ended and the trails were checked.
The park now closes for a full day each month for "Ijen Rijik", a cleaning and conservation programme; the remaining 2026 dates are 6 November and 4 December. It can also close at any time for weather, volcanic activity, field conditions or management decisions. Check the official booking site and the alert level on MAGMA Indonesia a day or two before you go.
What is the blue fire at Ijen?
Burning gas, not lava. Sulphur-rich gases escape from cracks on the crater floor at temperatures of up to about 600 °C, ignite in the air and burn with an electric blue flame, sometimes up to around five metres high. Some of the gas condenses into liquid sulphur that keeps burning as it trickles downhill, which is where the photographs of "blue lava" come from.
The flames burn around the clock but are too faint to see in daylight, hence the night hike. The size of the fire varies from night to night, and a USGS geologist told National Geographic he had heard that miners sometimes light sulphur to boost the flames for photographs. The park promotes the crater, the lake and the sunrise, so treat the blue fire as a possible bonus rather than a guarantee.
How hard is the Ijen hike?
Moderate; most reasonably fit people can do it. From the Paltuding trailhead it is about 3 kilometres to the crater rim on a wide, steady path with roughly 500 metres of climbing, taking one and a half to two hours. The first 2 kilometres to the miners' weighing post at Pondok Bunder are the steepest; the last kilometre is easier. A full night out, with the crater descent and sunrise, runs to about five or six hours.
The descent is the hard part: a rough, rocky miners' path into the crater, 30 to 45 minutes down and longer back up, often in thick fumes, by headlamp. If the wind pushes the plume onto the path, visibility can drop to almost nothing within seconds. Afterwards a path along the rim leads to higher viewpoints over the lake for sunrise.
Can you still walk down to the blue fire?
Sometimes, depending on the day. Even at Level I (Normal), PVMBG's standing recommendation has been that visitors and miners should not closely approach the rim or descend to the crater floor, and that nobody should stay overnight within 500 metres of the crater. When the alert level rises, as it did to Level II in July 2024, the floor is formally off limits. Guides go down when park staff allow it and turn back when they don't, so do not plan around a descent from an old itinerary; the rim and sunrise are still worth the climb.
Gas, safety and the health certificate
The main hazard is gas. Sulphur dioxide stings the eyes and lungs, and the lake can release invisible carbon dioxide that pools in low ground; in March 2018 a gas release sent around 30 villagers for treatment. Bring a respirator with filters rated for acid gases, since a scarf or surgical mask does very little, and check that a rented one's filters are not spent. The walls are dangerous too: in April 2024 a visitor died after falling while posing for a photograph near the edge.
The park does not recommend the hike for people with heart disease, asthma, respiratory infections or other breathing disorders. Every visitor must bring a valid health certificate issued no more than three days before the visit, checked at Paltuding. In 2024 no clinic there was issuing them, so ask your hotel or operator in Banyuwangi where to get one. Tickets do not include insurance.
Opening hours and booking
The gate at Paltuding opens from 02:00 to 12:00 Western Indonesian Time (WIB). Tickets are sold online through AyoKeTamanNasional, the name must match your passport, and they cannot be cancelled, rescheduled or refunded. East Java is one hour behind Bali's WITA, so 02:00 in Java is 03:00 on a Bali clock. With about two hours to the rim, the blue-fire window is short: be at the gate before it opens.
| Ijen at a glance | Details |
|---|---|
| Managed by | BBKSDA Jawa Timur (TWA Kawah Ijen) |
| Trailhead | Paltuding, Banyuwangi side |
| Gate | 02:00 to 12:00 WIB |
| Booking | Online, ID must match, non-refundable |
| Health | Certificate issued within 3 days of the visit |
| Monthly closures | Ijen Rijik days: 6 Nov and 4 Dec 2026 |
Getting there and where to stay
Banyuwangi, on Java's far eastern tip, is the usual base, with its own airport and trains. The drive up through Licin district to Paltuding takes one to one and a half hours. From Bali, the car ferry from Gilimanuk to Ketapang runs around the clock and takes about 45 minutes, though queues can add much more; tickets are on ASDP's Ferizy app. The crossing closes completely on Nyepi. Rather than an overnight tour with no sleep, cross in the afternoon, rest a few hours in Banyuwangi, then hike.
Banyuwangi town has the widest choice of hotels; Licin and the lower villages cut the night drive. On the Bondowoso side, Sempol and Blawan on the cool Ijen plateau have plantation guesthouses and the Blawan hot spring, and the road joins the same trailhead. A licensed guide is strongly worth it for the crater descent, and a tour from Banyuwangi bundles transport, mask, ticket handling and help with the health certificate. Be wary of any package that guarantees the blue fire.
When is the best time to hike Kawah Ijen?
The dry season, roughly May to October, is the best time to hike Ijen: the trail is firmer and sunrise over the crater lake is more often clear. The rainy season, roughly November to April, brings cloud and wet, slippery scree. Weekdays are quieter than weekends and holidays. Avoid the Ijen Rijik days, and leave a spare day for closures or cloud.
What to bring
Nights are often around 10 °C and can fall to about 2 °C. The park requires anti-slip shoes, a warm jacket and a mask; add a hat, gloves, rain shell, headlamp, passport, booking and health certificate. Do not light fires on the trail.
Quick answers
What makes the Ijen crater lake so unusual?
The Smithsonian calls it the largest body of natural hyperacidic brine in the world: about a kilometre across, around 200 metres deep, with a pH close to zero. Its last recorded eruptions were steam-driven bursts in 1993, 1994 and 1999.
Who are the Ijen sulphur miners?
Local men who cut sulphur from the crater floor and carry 75 to 90 kilograms out by hand, often twice a day, with few proper respirators. Give anyone carrying a load the right of way, and ask before photographing them up close.
Is a tour better than going independently?
Independent works if you book online, bring a health certificate, hire a driver for the night and engage a guide at Paltuding. A tour removes most of that friction.
Can I combine Ijen with Mount Bromo?
Yes: Bromo for one sunrise, a day's drive east, a night's sleep, then Ijen. They are separate parks with separate closures, so confirm both. Our guide to watching sunrise at Mount Bromo covers that half.
For the geology and history, see our Mount Ijen volcano page. Our Discover Indonesia: Mount Ijen, Java and Bali guides go further; browse all our guides.
Facts checked October 2026. Opening days, booking and health rules and crater access change often and can close at short notice; confirm with BBKSDA Jawa Timur on the official booking platform and check the alert level with PVMBG on MAGMA Indonesia before you travel.
- Nature Recreation Park Kawah Ijen: hours, rules and 2026 closure calendar (BBKSDA Jawa Timur / Ministry of Forestry)
- TWA Kawah Ijen kembali dibuka hari ini pasca kebakaran (Jawa Pos)
- Ijen (Smithsonian Global Volcanism Program)
- PVMBG Turunkan Status Gunung Api Ijen Jadi Normal (Ministry of Energy and Mineral Resources)
- Status G. Ijen Meningkat (Ministry of Energy and Mineral Resources)
- Status Gunung Ijen turun jadi Waspada (Antara)
- Aturan baru ke Kawah Ijen harus bawa surat sehat (Jatim Times)
- Stunning Electric-Blue Flames Erupt From Volcanoes (National Geographic)
- Ijen Crater (Wonderful Indonesia)
- 3 jalur alternatif ke Gunung Ijen (iNews)
- Jadwal penyeberangan Gilimanuk-Ketapang (detikBali)
- ASDP temporarily closes two ferry crossings to Bali ahead of Nyepi (Tempo)
- East Java and Ijen: volcanic highlands, coffee and hot springs (Travel And Tour World)
- Gunung Ijen (Gunung Bagging)
- Tourist dies in plunge while posing for photo at Indonesia volcano (South China Morning Post)
