The Ijen Crater is a volcano in East Java, Indonesia, which is most known for its ‘blue fire’ and its lake that is filled with blue sulfuric acid. The Ijen Crater is not your typical tourist destination. For starters, it's located in a very remote area and there's no easy way to get there. Secondly, it's home to some of the most dangerous gases: sulfur dioxide and hydrogen sulfide gas.
The views are breathtaking, but you’ll have to work for it. We started our hike at 2 am and it took around 1 hour to reach the top of the crater. After reaching the top, you will have to go down again, into the crater. Both paths are very steep and a headlight is a must. You will also have to wear a gas mask (provided by the guide) to protect your lungs grom the gas. You should arrive at the acid lake before sunrise for a chance to see what the locals call the ‘blue fire’, which glows bright blue at night due to all the sulfuric acid that spills into the air from its boiling lake below.
After this, you will go up the crater again to watch the sunrise and enjoy the views.