Kawah Ijen, is a gargantuan volcano on the island ... which flows along the volcano before solidifying into yellow deposits. A two-hour hike is required to reach the rim of the crater followed ...

Kawah Ijen is a giant, active volcano on the island of Java with a crater that contains the world's largest acidic lake. The water has a pH lower than 0.3 in parts of the lake where hydrothermal ...