One of the most surreal things i've ever witnessed. You start hiking around 1-2am, its steep and rocky and pitch black except for headlamps, but its all worth it for what happens at the crater. First you descend down into the crater itself (careful, this part is properly slippery) to see the blue fire — electric blue flames coming off the sulfur vents, doesn't look real, like something from another planet. Then as the sun comes up you get the turquoise acidic crater lake revealed in full daylight, absolutely stunning. The sulfur miners working down there carrying insane loads up the crater walls really puts things in perspective too. Fair warning, this gets extremely crowded, especially on weekends and holidays — go on a weekday if you possibly can. Bring a proper gas mask (some tours provide these, check beforehand), warm layers for the start since its cold at altitude, and decent footwear because the path down into the crater is narrow, steep, and gets genuinely dangerous with that many people on it. If you dont get there early enough you might miss the blue fire before it gets light, so leave with plenty of buffer time. Physically demanding but absolutely one of the best experiences in Indonesia, dont miss it.

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DO NOT RISK YOUR LIFE!! The blue fire is fake and the amount of effort you put to reach the destination is not at all worth. You can simply enjoy the trek and the amazing turquoise lake after the sunrise. One of the guide was mentioning that since 2015, there are 6 deaths happened among which 2 fell from the crater unknowingly, 2 fell while working, 1 fell into the lake and got cooked. There are no safety measures or any thing to hold while getting down the crater to see the blue fire. Our guide himself told they are just showing an example of the blue fire.

+3

I didn't get to see the blue flames at all, because a) I was hiking solo without a gas mask, and b) the access was closed at the time of my ascend. However, going up to Kawah Ijen and seeing the world's largest acid lake is still a real treat. The trip is easily done with a rented scooter from Bali, if that's where you are staying. You get on a ferry boat, drive to any of many guesthouses on the slopes of the volcano, sleep early, get to the ascend point by 2 or 3, pay your ticket price and go up. If you have a gas mask, great, if not, it wasn't that terrible (unless, of course, you do go down the crater for the blue lights but it sounds reckless with thousands of people who go every day). You don't need any guides for the top of the crater. In fact, all they'd do is rush you, and you might miss the clearing of the skies if it's cloudy when you go up. That's what's happened to me - all the groups left before the crater revealed itself in its fully glory. It ain't Bromo, but it's actually easier to DIY, and to me, still very cool.

+1

The blue flames and blue fire in Ijen were an incredible sight! It was real and truly beautiful when you witnessed it firsthand. If you’re planning to see the blue fire, hike to Paltuding at precisely 2 am to avoid crowds. Be aware that the path down to the crater is quite challenging, so make sure to maintain your three-point contact principle. Stay down there for a maximum of 15 minutes, as the acid gas is frequently blown towards you by the winds, which can cause irritation to your eyes and throat. Also, avoid getting too low on the crater (like squatting too long) to prevent the H2S hazard.

+3

Nice view but very subjective to weather with the heavy fog and the sulphuric air. Once clear, the blue lake is very beautiful. Hard climb up , not recommended for those that do not have right stamina, although there is lot of porters there waiting for business to pull you up at a cost , estimate 1mil Rupiah/ person. You need to engage guide. Can’t go up on yr own.

+3