The wild road to the blue fire of Kawah Ijen

Nestled between Banyuwangi and Bondowoso in East Java, Indonesia, Mount Ijen is home to the stunning turquoise crater lake, Kawah Ijen (Ijen Crater).

The adventure to this incredibly acidic lake, famed for its sulfur deposits, starts above the Ijen Plateau. The 3.2 km (2 mile) unpaved road begins at Pos Perijinan Kawah Ijen, the starting point before you ascend. It's a bumpy ride to the trailhead, followed by a 1.5-hour hike, including some pretty steep sections. Once you reach the crater rim, you'll likely see miners carrying heavy baskets of sulfur. The lake itself is a reservoir of sulfur, where it's mined daily. Watch out for the miners carrying incredible loads (75-90 kg!) up the trail. This sulfur mining has been going on since 1968.

The acid lake here is the world's largest! This volcano is famous for its electric blue fire, acidic crater lake, and the grueling sulfur mining. This sulfur, nicknamed "Devil's Gold," gets its name from its yellow color and the dangerous conditions. The water is so acidic it can dissolve flesh, clothes, even metal! Seriously, within 15 seconds, it can start to decompose human skin. Swimming? Definitely not recommended. You can descend into the crater, but be quick and at your own risk. Masks are crucial to avoid inhaling those toxic fumes. It's incredibly hot, smells awful, and the air is terrible, making a long stay pretty much impossible. Don't touch anything, and definitely don't touch your face. In 2018, the crater was closed for months because of toxic gas emissions, evacuating hundreds of locals.

The road is super narrow and incredibly steep, making a 4x4 absolutely necessary. No private vehicles are allowed.

In recent years, Kawah Ijen has become a popular tourist spot. One of the big draws is the "blue fire," one of the only places on Earth you can see this phenomenon. When sulfuric gases meet high temperatures, the sulfur ignites, creating blue flames. You can only see these flames at night, though they burn 24/7. Temperatures can reach a scorching 600˚C (1112°F), but the blue flames are only visible at night. Sulfur ignites at 360˚C (680°F), but a chemical reaction causes the blue hue, not the temperature.