Ijen crater is located in the eastern part of East Java. Administratively located in Bondowoso and Banyuwangi Regency. This crater is standing among other mountains such as the active Mt Raung (3,332 M), Mt Suket, Mt Pendil. You can reach from Banyuwangi or Bondowoso. Road to Ijen from Banyuwangi is considered as very bumpy that you will need a 4×4 transport.If you are from Surabaya you can access from Bondowoso as it is closer and road is not that steep and better than via Banyuwangi.
This green tosca crater lake lies hidden in the bottom of a giant bowl of Ijen Plateau summit, with depth of 200 m, and known as the biggest acid crater in the world with PH of 0.5. To get to this beautiful crater, you need to trek for 3.5 KM from Paltuding to the crater rim with steep mountain track. Once you arrive on the crater rim your hardship is worth effort. The smell of sulfur will thrill your nose more when you are closer to the crater. It usually takes patience to see the crater lake because sometimes wind blows with the smoke all over and blocks your sights. Just wait until the wind goes another direction that will make clear exposure of the crater.
Other interesting to see is traditional miners collecting sulfur from solfatar located at the edge of the crater lake. Everyday they transport the sulfur on foot from down the crater to the foot of Mt Ijen. One man usually can carry up to 80 KG of sulfur blocks with bamboo baskets. More than 20 tons of sulfur is mined everyday and scientist said that that is only 20 % of the total production, this limited exploitation is because of the difficult access. Sulfur is used as medicine material and also to whiten white sugar. Few sulfur miners have to stay overnight at the crater to watch over the pipes to mine the sulfur from burning. Only few miners possess mask to avoid inhale sulfur in the air that is very dangerous for human respiratory system.
At night the temperature can reach 5 degrees Celsius. And Ijen crater at night is very spectacular where you can see blue flame come out of the Solfatar which is actually the burning sulfur after meeting oxygen.
A dam was built by Dutch to prevent the acid crater water flow to the surrounding to endanger crops and people health.
What to prepare : Sneakers, sun block, hat, mask, raincoat/umbrella