It is safe to say Mount Ijen is not your typical hike. You don’t start most hikes at 2 a.m. You don’t need a gas mask for most hikes. But then again most hikes don’t take you up a volcanic crater to witness one of only two places in the world with “blue flames”. They don’t let you marvel at a bright emerald lake and watch as molten hot liquid sulfur turns to a solid in the span of a few minutes. Ijen does all of this and more.

From Banyuwangi’s Blimbingsari airport we drive for two hours to a small homestay outside of Blawan, luggage strapped onto the top of our adventure jeeps. The city gradually fades away with misty mountains taking its place. We stick our heads out the window as the road curves towards the setting sun.

Excitement jerks my body to alertness even before my alarm goes off at 1 in the morning. The stars and near-full moon twinkle brightly enough above us that we don’t even bother turning on our headlamps as we start hiking. Two short hours later we’ve made it 3 km to the top where we don gas masks before heading down into the crater. Men with large baskets pass us going up; they are harvesting the now cooled formerly liquid sulfur that spews in abundance from vents in the rocks here. Their loads of bright yellow waxy sulfur stalactites, our guide tells us, range from 70 kg to 120 kg (150-260 lbs).

We stand silently watching blue flames dance in the night. The blue glow is actually caused from the combustion of sulfuric gases meeting with the surrounding air, but as we stare at the rivers of undulating light it’s hard to focus on the science behind such a uniquely spectacular sight.

At sunrise we exchange the glow of the flames for that of the sun. Pink touches the sky above the crater and for the first time we can see our surroundings. White rocks give the landscape a lunar feel, while trees cover foggy ridge lines to our right. Some of the plants found here on the highlands are found nowhere else on earth. The warm crater lake looks so inviting with vibrant turquoise water, but with a pH level of almost 0 this highly acidic lake can dissolve clothing and human skin.

We touch nothing and take only photos before starting the walk down. From one wonder to the next Kawah Ijen never stops surprising. It is a landscape as diverse and beautiful as it is deadly and well worth the early wake up.